dispensaries are confusing

my dealer buddy has been off doing whatever so i started to switch over to dispensary weed and i am overwhelmed by the options. bro usually brings 3 nice bags of bud and we smoke a little of each and i buy what i like. here u cant really test it. thats not a major issue its just like, whats the fucking difference between all this shit? preground, full bud, carts, disposables, edibles drinkables you name it, why should i want one over the other? and which should be more cost effective? should i just stick to flower or would getting a battery be better or should i get the shake and shit they mush up for you i think its cheaper i guess? idk

tldr: what should i get at the dispo