All of them!
Random Chess Problems

In this position, taking the bishop leads to a draw like on this graphic, so let's not do this and make a queen differently.
In this position, with we move the king the wrong way, we will make a draw. What to do after making a queen ?
Go subscribe to Chess Vibes on youtube, he made a detailed video about this problem !

I wasn't able to solve puzzle #4. After some trial and error I managed to get a 'Solved', but it still didn't feel satisfying. Beginner level puzzles should be easy for me and this didn't even feel like a challenging puzzle. I saw the solution almost immediately, but alas, not good enough.
I'll take comfort in the fact that Stockfish also wasn't able to find it.
On a more serious note, please make sure your puzzles are CORRECT. I guess it's not deliberate, you probably just messed up the pawns accidentally, but this is not good. Not only was the move you want white to play the wrong one, you're also having black play a terrible move that's impossible to anticipate. Now that I think about it, even if you had chosen dxe5, you can't just let black play dxe5 either. You should not make a puzzle based on what the ideal response will be by the opponent, even when it's supposed to be a beginner. That's not how beginner puzzles work.

I wasn't able to solve puzzle #4. After some trial and error I managed to get a 'Solved', but it still didn't feel satisfying. Beginner level puzzles should be easy for me and this didn't even feel like a challenging puzzle. I saw the solution almost immediately, but alas, not good enough.
I'll take comfort in the fact that Stockfish also wasn't able to find it.
On a more serious note, please make sure your puzzles are CORRECT. I guess it's not deliberate, you probably just messed up the pawns accidentally, but this is not good. Not only was the move you want white to play the wrong one, you're also having black play a terrible move that's impossible to anticipate. Now that I think about it, even if you had chosen dxe5, you can't just let black play dxe5 either. You should not make a puzzle based on what the ideal response will be by the opponent, even when it's supposed to be a beginner. That's not how beginner puzzles work.
Really sorry. I once discovered that trick and I was so exiting. Thanks for your comment, I need to admit that I'm not a good chess puzzle maker !
Anyway, I'll change the problem soon for a better one, but I first need to check something :
I'm pretty sure about it but when you where saying "puzzle number #4" you where taking about the puzzle number and not the comment number ? the comment #4 has a puzzle I think is pretty well done.

Huh... I don't know how you did that, Farfous, but this is kinda strange that you got to put a sentence in a quote that no one says, tell me if I'm wrong.

Puzzle for 200-400
In those kinds of position where you think you are losing your rook, don't PANIC !
Just move the bishop to attack the queen and protect the rook by X-ray.
(For the guys you don't know, X-ray is for exemple attacking a queen on the same diagonal as a rook with a bishop. at the end, the queen moves and you take the rook.)

By the way, moving the knight is saving the rook too, but I usually prefer to KICK completely the queen out back in White's territory.

How do we win the black queen here ?
By the way, if you think black can just go protect his queen with his king, take a look at this :
So this is definitely winning for white. Stockfish is saying M3 after we take the queen (if rook takes rook) and +18.1 if white sacrifice the rook for queen and bishop.

In this position, white's knight is trapped, so he pushed his pawn to make a square where he is protected from the bishop. What to do after we attack the knight with the rook ?
Checkmate for beginners :
Win material for beginners :
Tell me in the comments which ones you solved from the first try ! ^^