Back in the day they were separate, they were all combined a long time ago. I did a search in-game “Loremaster” and the result was Legion and Shadowlands but they will tell you to load up the normal leveling guides anyway, that’s because as all the guides covers loremaster. I hope that helps
I would look for the loremaster in wowhead.com and use an addon called quest completist, if you’re looking for a specific quest you can type /qc and search by name etc. Quest completist will also show ! on the big map.
If you fire up some of the guides it should start flagging quests that are complete, you may need to manually tick of some steps. It should find quests that aren’t completed, there’s good info in wowhead.com, if you’re stuck look at the comments.
You’re always welcome to post in here, most of us skilled folk would try to point you in the right direction.
I wish you luck