not sure if your question is about the process of getting a card or if it's about trying cannabis for the first time, but i only have experience w/ the latter.
There's a few different ways to do it, and each one has a different kind of high (but they're all very similar imo), but smoking ofc is the most common one.
Smoking, vaping, edibles, and even using a bong instead of a joint all have slightly different highs. Smoking & vaping in general work right away, and it's important to take it slow and make sure you don't over do it.
You technically can't overdose, but you can very much have a bad trip if you go overboard. Don't worry though, as long as you listen to your body you should be alright! When i first started, i was only able to do one or two puffs and i was good for the rest of the night. Now i have to do a half gram to actually get high, but if i do less im able to function and it still decreases my pain.
I've only ever tried a few edibles before, and even then i was using them to help me sleep more than for pain. They usually take 30min-an hour to kick in though & you should keep in mind just how much THC is in it; if it's higher concentration, definitely do less on your first go.
Cannabis has a lot of different strains, and there's apps & websites that can show you what people have reported feeling for the side effects of that specific strain & even the flavors of it. Some make you sleepy, some make you energized, some make you aroused even!
There's indica, sativa & hybrid mixes of the two.
If you're a more anxious person then i would suggest trying indica and indica dominant hybrids first. Sativa can be really intense for some people, I know for me personally it is but with how high my tolerance has gotten it doesn't effect me negatively in any way.
indica is really good for making you tired and/or relaxed, and sativa can be more energizing. But it usually depends on the specific type of strain that that joint/edible/flower/etc has, so if the dispensary you're going to has a website then they will most likely have a list of what they have in stock.
Before you go in, try to check if they list what's available because that can give you a more clear idea of what strains they have. The dispensary i go to has a menu online, and for certain products if you click on them it will list the side effects & even the flavors of said product. Weedmaps is also a good app for finding out more abt that sort of stuff, and they also tell you what dispensaries are near you!
Just remember to pace yourself, watch your reactions and have a good time haha!
Personally cannabis has been a life saver for me. I use it to go to sleep & to do chores. I hope you're able to get a card easily & it isn't a hassle, good luck!