Need Nutes

I know I have a deficiency but I have no idea where to look for nutes or what kind to get. Can I just get one bottle that will work or do I have to get a couple different ones? This is my first grow, so Im not looking for perfection, I just want to try to smoke my own home grown medicine. Its been about 8 weeks now.

want it simple? Miracle grow... Dilute it and go easy on em, and flush regularly.
Want to dial it in? there are better people that can answer that in more detail.

Is that safe to smoke after? I think I read somewhere that you're supposed to stop feeding them about 2-3 weeks before you harvest, is that enough time to get it out? How often would I want to flush?

You can give nutes on the day of harvest and still be smokeable. The more you grow the more picky you will get and you will be able to taste the nutes. A 10 day flush is typically enough.
As far as nutes its hard to miss with dyna-gro (foliage pro and pro-tekt) they are simple to use, affordable and work wonders.

Flushing before harvest is debatable. if you only have a couple weeks to go, feed until they are looking good, then do a light flush at the end

General Organics go pack is fairly cheap.

Any guess how long I would have until harvest? Growth has been almost non existent the past two weeks so I'm not sure if itll suddenly bloom when I start feeding them.

Is dyna-gro something available in most stores? (Wal-mart, Menards, etc..)

I wouldn't expect much more growth out of them in the 16 oz cups.
Probably have 3-5 weeks left imo, but they aren't my plants so i really don't know.
No nutrient that you get at walmart will really be worth it.
Dyna-gro is probably one of the easier to find, may need to go to a gardening center or place the sell plants to the public, you will most likely be able to find at least grow and pro-tekt, i feel the pro-tekt is one of the best products on the market and would use it regardless of other nutes.

So would I be doing a combination of both products at the same time?

yeah its like 5 mls per gallon of water for each, so very little of each.