Which one should play first classic of retail ?

The only thing I have played wow was playing Wotlk on a private server in 2014 but in addition to reaching level 80 it did not get very far But which one should I play first I always wanted to know Eastern Kigdom and Khalimdor completely and see all their quest raid and dungeons and say goodbye to the continents before the cataclysm.But I'm excited shadowlands and I don't want to start the expansion late And I also want to do the entire LEGION TBC and WOLK storyline. and soloing raids and dungeon.