What a job you've taken on! I do hope that you are going to have the cake done by someone else, unless you've got excellent skills. A wedding by itself is nervewracking enough.

Almost all of the appetizers done with phyllo can be frozen but they have to be baked the day of. Will you have someone to help you with that? Most of the stuff that I have that you can do ahead, will need baking right before serving.

You can fill phyllo pockets with sauteed, chopped mushrooms or a spinach filling. Empanadas can be made ahead and frozen. Stuffed mushroom freeze well, if you stuff them with pecan/mushroom filling. Dips don't freeze well, unless you are doing hot ones that will be heated like chile con queso or chile. You can also use the skinny French bread loaves, hollow them out and stuff them with things like a ground ham mixture and freeze those.
In many ways, it might be easier to serve a whole meal than to do just appetizers. Casseroles are so easy to do ahead and freeze. Appetizers, because they are small can so easily dry out on you and a whole casserole would not do that. Also marinated beef roasts, can be done a day or two ahead and then just thawed and sliced thinly. But those are expensive, because you need very tender meat.
What time of the day are you planning on marrying? That makes a difference in what you will want to serve. How many people and what kind of budget are you planning for.
The *first* thing in any party planning is the budget! Set that and be sure to give yourself some leeway in the amount but be as firm as you can possibly be.
You budget needs to include any rentals you may need or the purchase of plates and utensils and serving dishes. Don't forget invitations, flowers, decorations, entertainment, etc. Unless this is to be a very small wedding, you may need to include the hiring of helpers to serve, prepare drinks, etc. and just to keep the food out and hot and help with the clean up. Once you get those things settled, then you begin to plan on the food and the serving of it.

Get back to us, Marjorie. We need more information in order to really help you. Just throwing a bunch of recipes at you, won't be much help and will only confuse you. Some things are cheaper to hire out and some things are definitely cheaper to do at home. Often a combination is a good thing to use. It eases your burden and keeps your nerves in a little better shape.

BTW Best wishes to you on your upcoming wedding. It's a wonderful time and a joyous one.