I can't offer advice on how to ship them, but maybe someone on here is local or semi local to you and would buy it. A first step would be maybe put where you are from (state or country, don't have to have city) so maybe someone can take a look. Another bit of info is putting what you expect to get for the cards. If you had them for 20-30 years that would place them from the 80's to late 90's (if not earlier). Another member with cards from that era is selling some and said he wanted 1-4 cents a card. So I guess my advice would be when you are ready to sell them (don't forget to use the Selling forum and not the General forum) be as informative as possible. Since you have them all listed you don't need to show checklists, but on the post you do, maybe put you're state, how much you want, and maybe mention a couple of the better cards you have to entice people to look at what else you have. If you have no takers, consider splitting them up into smaller lots and go from there. Welcome to the site, by the way, and hope your cards find a new home. I have a few I need to get rid of too, maybe once I'm done going through all of them I'll sell them on here too and use other advice you get as guidance.
Royal Card Review is my blog if you feel like checking it out, thanks if you do!- royalcardreview.blogspot.com/
In the process of updating my collection so don't trust any of my lists right now.