If you want to practice with legal plants first, learn basic tomato growing. Cannabis and tomatos have almost the exact same growing pattern. Catnip is a good one to practice on as well.

I suggest practicing on some bagseed. The seeds are free, so why not.

Growing cannabis is not really that complicated at all.

Germination requires only dampness and a dark room. Take 2 paper towels, take a saucer plate, take one paper towel, soak, place seeds on top of first layer, place another layer on top, soak. Keep the paper towel moist at ALL time, but no sitting water either.

Once your seed pops and gets a small taproot, you can now transplant to dirt.

Once you have that step done and down, read about Vegetative growth, what is needed, then do it. Give yourself a few days to read and gather supplies for the next step, then do it. The best way to learn is to grow it, make your mistakes, then not make those mistakes again. Some people make no mistakes hardley. It's like learning to play an instrument. Sure, you can read about it, but when the time comes to play, you have no clue what to do.

If you ever need growing advice, just ask.