Good deal stoner!
Whether or not you will have herb worth keeping is highly variable with bagseed. A lot of times, when I first started growing, I would plant quite a few, as I knew about half the population would be males, and about another 10-30% of those left over would just be crap. But in the end, I would always wind up with quite a bit of decent smoke. At least for me and a few friends.
When I was doing this, I didn't bother with paying for soil or nutes. Although I did hit them with Miracle Grow from time to time.
As for what I harvested in actual weight, at the time I wasn't too much into it and never bothered to measure, nor did I have a scale at the time.
But in my experience, growing outside is super easy! Mother nature pretty much takes care of it. I did water them, but that wasn't even needed as much as I probably did. My main problem was keeping things hidden, as some of them were so tall they would peak over my 7 foot fence! And if someone was paying attention and knew what to look for, you could clearly smell herb if in the vicinity.
I would advise you to have fun with it, plant as much as your space will allow, and try not to mess with them much. Don't think you're going to increase yield or growth by taking a pair of scissors to them. New growers tend to like to cut off foliage thinking they are allowing more light to reach their plants..... A BIG NO-NO!!!!!!! Just let them do their thing, especially as you are learning. The more green your plant is, the MO-Better!!!!