A lot of people have given good information here, but I think right now you seem to be experiencing overwhelm, and you may need a bit more experience to make sense of it all. So I'm gonna start you off very simple.

Buy a packet of snap peas. Little Marvels are good, but any snap peas will work.

Get a growing container. If you can find a milk crate, that'll work. You can line it with the burlap from a bag of rice, or with garden cloth.

Fill it with dirt. There are a lot of cool things you can do to make dirt, but we're doing dead simple. Buy some soil at the store. Garden soil or potting soil will be fine.

Sprinkle your peas over the dirt. Push them in so they're covered by dirt.

Water daily on days it doesn't rain. The goal is to make sure the soil doesn't dry out.

When the peas sprout, put something into the container for them to climb up. Wooden stakes are usually good for this.

Harvest peas as you see them. They can be eaten raw or cooked in various ways.

Eventually, they will finish producing and die off. You will notice them going brown and shriveling up. Once you reach this stage, look up how to compost. That will be your next step.

Once you have built confidence with the above exercises, start looking through seed catalogs for next spring to figure out what you want to grow. Then come back to Lemmy for advice with a list of the plants, your location or growing zone (you can look your growing zone up online) and some information about the space available to you to garden and whether you'll be doing it as containers on a patio vs. in dirt, etc.

Also, check out c/gardening, as well as potential related communities like balcony gardening and hydroponics.