Sorting/Organizing

Not sure if this topic belongs here, I have thousands of baseball cards stored in boxes, that were given to me, and that I collected through out the years when I was younger. There is no organization to them (brands, years, teams) they’re pretty much all randomized into boxes. I’d like to go through them and see what I have and organize/ sort them along the way. What’s the best way y’all have found to do this when you have so many cards, and with this many how do you find the valuable ones without searching every player of every card? Also do you sleeve every single card or only the ones the mean the most to you?