I recommend learning this next:
https://sarah.cubing.net/skewb/my-method#section/beginners-variation
This is what I know and I average 13s with relatively little practice.
I had trouble understanding the diagrams, so I'm going to explain a couple of the steps that took me a long time to figure out and hopefully it will make more sense for you.
First side: you should already know how to do this, the two example cases shown helped me with inserting the last corner.
Remaining corners: When you get two headlights, hold them on the right and perform a sledgehammer (R' F R F').
When you get two corners facing up, hold them so one is in the front left and the other is on the back right and the corner in the front right has yellow facing you, then perform a sledgehammer and it will create a headlights case.
Solving top center: Rotate the skewb with y moves to put the yellow center in the back. Then do a sledgehammer, y2, and another sledgehammer.
Solving last centers: Hold the two solved sides on the left and right sides (it doesn't matter which color is where as long as they are on the left and right sides).
If there are 4 centers that need fixed, do a sledgehammer, y2, and another sledgehammer, this will create a case where there are 3 centers that need fixed.
If there are 3 centers that need fixed, rotate so the solved one is on the bottom (using x moves, keep the first 2 solved sides on the left and right). Then, look at the top color of the corners, find the center that needs to go there and hold it in the back. Then do a sledgehammer, y2, and another sledgehammer.
To improve after this:
Be color neutral
Learn the polish finger trick for sledgehammers
