I just watched a TikTok video of 2 players rated in the 1700-1800 range. It was a king and rook against a king and knight. The player with the rook was unable to win the knight or the game. With perfect play on both sides, should this be a stalemate or a win for the rook side?
Should be a draw usually:
I’m a professional chess coach (semi-retired now 
)
What Pulykamell said is spot on.
If you want to see this for yourself, you can use chess tablebases (where all possible positions have been classified by computer as win or draw.)
Typical draw:
KRvKN – Syzygy endgame tablebases
Forced win (King and Kinght separated)
KRvKN – Syzygy endgame tablebases
Forced win (King and Kinght poorly placed)
KRvKN – Syzygy endgame tablebases
In the British Championship, I was playing a Grandmaster (I’m a FIDE Master.)
He had the advantage throughout, but in an ending I managed to exchange off all the pawns and reach a drawn King + Rook v King and Knight ending.
I was so relieved that I offered a draw. 
The Grandmaster (who I knew well) gave me a look. 
After a while he took the draw, but then stated “It’s not good form to offer a draw in the worse position against a stronger player!”
I’ve not repeated that mistake since…
Did you have the knight, or the rook in that game?
I had the knight (sorry if that wasn’t clear) - so the Grandmaster could have played on to test me out…
And here’s the game:
I see that your other game against him ended in mate. The guy might be pretty stubborn.
He was much younger when he lost to me!
I’m sure you were clear, I’m just a low Elo player and trying to follow along.
In case it’s useful for anyone: note that “stalemate” and “draw” are not synonyms. There are many ways for a chess game to end in a draw, and a statemate is just one of them. A stalemate is where the player whose turn it is has no legal moves but their king is not in check. For the rook versus knight endgame in this thread, the draw would come via the 50-move rule (i.e., no captures or pawn advances in 50 moves) or by three-fold repetition (same position appearing on the board three times, not necessarily consecutively).
That’s what late night posting will do to a person.
Or, of course, through the most common way that games end in a draw, by mutual agreement. The 50-move rule and the three-fold repetition rule are just there in case one of the players gets stubborn.
And, honestly, if the OP is lower ELO player it’s probably best to play on at least for a while with the Rook. It’s not too hard at all to screw up the defense with the Knight against a Rook. And worst case you get a draw, since the Knight and King alone can’t mate.
The game I was watching on TikTok was blitz chess and it like it would have been very easy to mess up on either side.
Well, that path (if allowed by the governing rules of the game or tournament, which isn’t always the case) does not relate to the question at hand, which is whether this is a theoretical draw or not. I know you’re mostly just picking a nit in the wording, but in that case you should also mention that the players could stumble into an actual stalemate with these pieces, could end up with a draw by insufficient material, could end with a side claiming insufficient losing chances in time trouble (ruleset dependent), could end with arbiter intervention with the 75-move or five-fold repetition rules, or probably something else that I’m not thinking of off the top of my head.