Haven't gotten a 5e game going yet, but from what I've seen, as far as adventuring in my homebrew campaign setting, the following edits will be made...
Entirely
- No Tieflings.
- No Dragonborn.
- No Tinker Gnomes.
- No Aasimar.
- No "Eladrin."
- No Sorcerers. All arcane magic-users, collectively referred to as Mages, have some level of "spontaneous" casting. The Wizard/Sorcerer split never came to Orea.
- No Planescape originated locations, races or classes.
- No Eberron originated races or classes.
- No Dragonlance originated races or classes.
- No Evil PCs.
- No Halflings that wear shoes...and NO Halflings that resemble anything like the monstrosities that are presented in the PHB.
Partially
- No Barbarians as written. Barbarians in my campaign world are a human culture/race/class. They do not function as PHB presented Barbarians.
- No Drow as a PC race.
- No Wood Elves as a PC race (at least to start with).
- No Half-Orcs as a PC race (at least to start with).
Not sure yet
- Bards as written.
- Warlocks as written. But interested in giving one a try and seeing how it goes.
While I have certainly never used every possible creature in any given Monster Manual, their presence in such a manual does not necessitate their presence in the game world...or their fluff or even appearance, in some cases, if they are. I will conceivably make room/find a way/place for them if they work for the story/adventure/game of the moment. Monsters "known about, in-world, by your every day person" are generally limited, however.