Opening theory and tactics are a good place to start.
An easy step is make sure you know a few common openings and have at least one response prepared to each. But also a good understanding of principles. Opening principles are more important, you can wing it if you don't know the theory. There are thousands of videos on YouTube about these topics.
And obviously just don't hang pieces and take your opponent's hung pieces. At 1300 on lichess, your opponent will make a bunch of tactical mistakes which you can just take if you see them, after you can just win if you play solidly for the rest of the game. The way to study here is with puzzles.
Sorry to patronize. I have played thousands of 1300's on lichess and improved after I sat down and studied. But I can tell you, if you're actually 1300 you are not strong enough in some of these areas.
P.S. I don't believe the comment above yours. The dude went from 2200 to 1300??