what checkmates should i keep in mind

For your level, try learning queen + king vs king checkmate, 2 rooks + king vs king checkmate.

already know those

try to lure the king into the corner then trap them 

for rook + rook just lead them to the starting position thingy and then use the other rook to checkmate

thats practically all i know though

i don't know how to checkmate with bishop or anything else

That’s not really important for your level. As long you know those checkmates, you can continue. Just check whether your intended move is a blunder or not, check whether there is a tactic (try finding forks), do puzzles often, play more games, and you will be above 1400 in a shorter time.

Here’s a checkmate you could try getting for a match if your opponent does the movements

I call it the king and queen duo checkmate

You can find most checkmates during the game as long as you have a basic understanding of how pieces work together, learning the king and rook and king and queen checkmates are all you need early on in your chess journey. You’ll do better to study other chess ideas before learning any of the other checkmates (like bishop pair). 

-Jordan

Do not fall for the fool's mate if you move 1.f3/1..f6.

I might be stupid but im, not that stupid