What Do i Need?

Champagne glasses for toast, garter, gifts for bp, gift for parents, groom if that applies.

Your venue or baker may have a knife for the cake cutting. If you are not doing a garter don’t need a garter and you should be provided with glasses to drink. They may not be fancy ones. Gift for BP, and parents. A card box. Any jewelry or hair things. A purse if you want one. Memorial table stuff if you are having one. Reception dinner dress. Tips for vendors.

Yes definitely make an inventory check of everything you need. Scan through how you'd want your tables to look like for your guest sign in table you can always do a mock of how you'd want it to look and then think about if it's missing anything, etc.

Cake standProgramsGifts for bridal party, parents and each other (if you want to give gifts to each other)
GarterSignsGuest bookFlower girl basket and ring bearer pillow (if you are having ones)
Table numbers
Menu (I would only do this with you are having plated meals)
Esort cards
Favors
Petals for flower girl to throw (if you have one)
Card box
Something old, new, borrowed and blue
Emergency Kit We are doing a candy bar so all of the candy, jars and take home bags for guests