For the record been smoking almost constantly for over 45 years.
Cannabis is a rather complex drug, and not like almost any pharmaceutical, in that it's composed of hundreds of compounds that are active and/or complementary, rather than a single isolated compound, or a few together, as found in the vast majority of medicines. The active elements are known as terpenoids, a class of chemical compound, and the cannabinoids themselves are a subclass of terpenoid (tri-cyclic if I recall).
Every genetically defined strain has it's own unique profile of terpenoids, a mix of hundreds of compounds, and even for a particular strain each separate batch grown can vary in that profile too (not to mention it's harvesting and curing effecting that). There are hundreds, more like thousands, of different active strains.
The actions of the various cannabinoids is on the body's endocannabinoid system which regulates a lot of the bodies internal systems, and the different cannabinoids a particular strain contains will modify the effects quite considerably (e.g. THC/CBD balance but many more compounds involved). On top of this, there are numerous other terpenes found in many common plants such as myrcene (found in hops), limonene found in citrus fruits (orange, lemon, lime etc), beta-caryophyllene (in cloves) and linalool (lavender) and so on...
These cause what is known as the entourage effect whereby it's believed they can also access receptors at the same time as the cannabinoids to further modify the effects.
And on top of all that complexity each person has their own profile, in terms of how they'll react to these mixtures of active compounds. And that will also vary through life, time of day, physical state, and so on...
Wrap that up with the fact that this incredibly complex interaction is woefully under researched and not well understood.
Since autism isn't a condition as such but rather a class of conditions that result in common symptoms (in autisms case social interaction, sensory conditions, etc), no-ne can say cannabis will help or hurt (or both at once) an autistic person. There are some known vulnerabilities - taking cannabis before the brain has fully developed can alter it's development so it's not recommended before early to mid 20's, some people have latent psychoses that may never become active but can be triggered (usually on a temporary basis) by cannabis.
Because of the lack of knowledge about both autism and cannabis and endocannabinoid system, the risks are likely to be higher for autistic people, but far from exclusively. But at the same time, it can also relieve some difficult symptoms for some, and can have value.
It appears to cover a range of types whereby those strains defined as Sativa are more likely to have a mild psychedelic experience and be more uplifting and energising, but also more likely to cause mental disturbance, in particular anxiety, paranoia and troublesome thought patterns. While at the other end the Indica leaning strains tend to be more soporific and calming, but can also suppress motivation and other unhelpful effects.
But each strain can be a different case, and only by trying can one find the strains that may help certain symptoms.
Like every ingestible substance in the world, cannabis has dangers. Just smoking it has serious health impacts (even sans tobacco). It's not generally considered addictive by most definitions, but most certainly can be habituating, and that can be just as much a problem.
Concentrates tend to have much of the natural additives found in cannabis, removed as part of the process, in fact, some concentrates are essentially little more than THC, and the manufacturer actually adds a mix of terpenes to try and make it closer to it's original profile when in the plant. This is not just for flavour but impacts effects too. Personally, I think if one finds a good safe reliable supplier of quality controlled cannabis, they are better off trying the natural product rather than processed items, though things like the live resin extracts are not chemically extracted and use techniques like pressure extraction that retains much more of the natural mixture of active compounds.
Bottom line, if you decide to try using cannabis for improving quality of life, and decide you're prepared to take the risk, the best route is finding a supply of well produced weed - grown and harvested cleanly, without using growth hormones and the like, properly flushed before harvest (to remove the chemicals it's feeding on), and be reliable in what strains are being sold - i.e. ensuring they are actually the strain it says on the tin. Then you can experiment carefully with various strains to find the one's that may help your condition.
I've kept this short and simple(!), there's much more to it and lots more aspects of interest and importance, but I've tried to give a less subjective summary of it as a drug and what it is. There's huge amount of ignorance and misinformation surrounding it which doesn't help matters.
If you can get by without it, that's very likely for the best, and hypocritical or not, I wouldn't recommend it, or at least encourage it's use. But that doesn't mean it can't sometimes be beneficial for some people in certain situations.
Also, avoid buying from dealers if at all possible. Many illicit cannabis farms do not produce medical grade - i.e. a known strain, correctly cleaned of any fertilisers and other additives before harvest (so you're not consuming poison!), correct preparation, consistent quality, and also guaranteed free of synthetic additives - some poor grade cannabis grown by unscrupulous people is sometimes sprayed with a solution of synthetic cannabinoids (colloquially know as 'Spice' often) which are extremely dangerous drugs and not at all like consuming genuine cannabis, even if it's a related chemical structure.
P.S. Another item of note - consuming via inhalation or sublingual absorption will produce different effects to consuming via the digestive system. The routes have different metabolic pathways and convert the compounds into different things. Route of administration also effects the timing of onset and longevity.