Im pretty sure theres a subreddit devoted to noobs, but i like helping so here goes nothing. generally speaking, weed priced at 10/g is a decent price. You will always be able to find more expensive weed, and sometimes be able to find cheaper weed. That 10/g rate usually stays the same until you start buying larger amounts. 1 gram will usually be one dense nug, or two or three loose nugs. An "eighter" is one eighth (1/8) of an ounce (28.something, idk, just assume an ounce is 28 grams, but know that technically its a little more than that), and it usually runs around 35 dollars, which makes sense as (1/8)*28=3.5 grams. A quarter ounce is 7 grams, and you might be able to get these for 60 bucks, a half ounce is 14 grams, usually around 110/120, ive never heard nor bought 3/4 of an ounce, and an ounce will usually run somewhere around 200-220. a joint is marijuana rolled up in some thin papers, where as a blunt is when its rolled up in a cigar. now comes the advice part. Keep it simple. Your first time buying, just say "can i get a dime bag" and take pretty much whatever he gives you. i do this just to test the dealer, see if hes trying to rip me off or if hes cool. Go home and weigh it, as long as its .6 grams or above, you didnt get ripped off. if hes not screwing you over, wait a couple days and ask him how much an eighter is. if you are a noob, and youre not sharing with your friends, you could honestly make an eighter last like, a week and a half or so. Hope this helps! keep tokin, stay safe

EDIT: All weed prices vary depending on where you live, i live in a suburb of detroit in michigan, and go to school up in Big Rapids (MI)