So recently I got a premium account in tf2. Does that change what type of items I get now in the weekly random drop? If so, what type of items should I expect?
According to the Free2Play FAQ, Free users can only obtain Standard items (in item drops, these are just simple weapons and crates), whereas a Premium user can obtain Standard along with Rare and Cosmetic items, such as hats/miscellaneous cosmetics, a certain limited range of Paint Cans and tools.
A full list of obtainable items and more information can be found on this page of the TF2 wiki.