The question is, do you want to save some or all of the stamps to start a real collection (right now, it is an accumulation) ...
here are some basics about inheriting a collection -
https://stamps.org/services/inherited-a-collection .. or here is an online book:
http://www.inheritedstampcollection.com/index.htm real collecting takes time and effort and can be a very enjoyable pastime
or do you just want to sell it? If the latter, find a stamp show and take the U.S. stamps to 2 or 3 dealers to see if you can get an offer
the stamps that are stuck together are not really collectible; if you get them unstuck you can use for postage (use glue, NOT tape) to attach them to envelopes