Which opening should I learn at my level?

The title has it all!

It's a good idea to look at openings. But at your level, I think the first goal is really to apply the principles of opening, and be ready to react (with the help of these principles) to every new opening line that you encounter.
Creating a library of openings encountered during different games also allows you to have in front of you the moves that worked or not (check them in a database https://lichess.org/analysis#explorer).
Simply learning the moves is a bit illusory (at least as soon as you get past the first 2-3 moves)
In "boost your chess", for the <1500 players; Yusupov explains gambit only for the <1500 players

London System

The opening you WANNA LEARN is the Right Opening. :)

The Philosophy of an Unorthodox Chess Opening

I enjoy chess but I'm not going to devote my lifetime to it. I do have other interests. That being the case I want to get the most 'bang from my buck' as far as the time I put into the game is concerned. That being said, studying the theory of chess openings not only strikes me as boring memory-work but pretty uninteresting as well. Couple that with the fact that I play correspondence chess, then theory seems for the most part, unnecessary

A few years years ago I decided to to improve my game I first had to develop some sort of opening repertoire. I wanted something with little theory and that was not tactical in nature. It also had to be an opening that was not mainstream and that would provide me with middlegame positions that I was comfortable with playing.

As Black, I settled on the Modern Defense, after reading about an obscure Canadian Grandmaster named Duncan Suttles. He was an unorthodox player who played an unorthodox opening (the Modern Defense). This appealed to my contrarian nature.

I liked the fact that it was a counter-attacking system which allowed White to set up his center unimpeded while attacking it later on, usually from the flanks. It's common knowledge that counter attacks have a greater chance of success than the initial attack. (this is especially true among ordinary players like myself).

The Modern Defense (g6, B-g7, D6) is closely related to the Pirc Defense (d6, N-f6, g6, B-g7), the difference being when playing the Modern, black delays the development of his king's knight.

As I was having trouble coming up with an opening system when I was playing White, I started to experiment. I thought why not play a 'Pirc Reversed' as White. The first four moves were automatic (d3, N-f3, g3, B-g2)...I didn't know it at the time but what I was actually playing was the King's Indian Attack but with a twist, instead of opening with e4 or N-f3, I started the game with d3.

Some would say that playing d3 as White gives Black all the advantage, but that is not necessarily so (especially with players of my caliber). Black is saddled with the problem of too much choice...sometimes that can be as much a hindrance as anything else. Like an Aikido master I adjust my play to however Black shapes his opening...

I don't even know openings at my level.

For your level https://lichess.org/@/TheAstroGuy you should play the Italian game.

The Italian Game, the Scotch Game, the Four Knights and the Vienna Game all seem like good openings to get going with. It's not worth spending much time on openings at your level, just pick something simple that gets your pieces out and gets you a game of chess. You also don't need loads of theory - have a look at how the first few moves normally go and then just try to play play sensible developing moves - if something you do in the opening gets you into trouble then go back after the game and work out how to do better next time.

since u are a fan of "space"(look his profile) it would make sense to chose openings that gain space.
the easiest way to gain a space advantage is to play gambits.