Gaea's cradle or any revised dual lands are things to look out for. Like every one is saying use the Tcgplayer app and scan to find out.

Ancient Tomb, Wasteland, Mox Diamond, Lion's Eye Diamond, Wheel of Fortune, Gilded Drake, Grim Monolith.

All high value old cards OP might have. There are lots of other mid value ones but this is a decent starter list.

Definitely don't just sell these in bulk to anyone without going through and checking prices. There are cards from that time frame worth $1000+ and many worth a few hundred. You will have people messaging you offering to quickly buy the whole thing from you, take your time and comb through it yourself.

Download tcgplayer, you can just scan every card with the camera to get an estimate of value. I really wish I had my old cards I had several boxes ranging from Arabian nights to homelands.