Express Action Sports

I’m a beginner photographer and I want to shoot portraits, landscapes, and sports(Action Sports to be specific). I’m already out of automatic modes( I usually shoot in Av). And I currently have a Canon T2i. I’m gonna get a 50mm 1.4 next month and hopefully a 70-200mm 4.0 for Christmas this year. But does anyone know of any lenses that would be good for shooting sports like skateboarding and rollerblading?

As others have said, larger apertures are important for sports. It allows you to run higher shutter speeds to stop action and the larger aperture reduces the depth of field so that your primary subject is the only thing in sharp focus.
You can go with a slower lens if you learn the techniques of tracking your subject so that they are not moving in the frame or choosing a peak of action where the subject is still (a border coming up from a half pipe to turn around and drop back in).

Speed costs money. The longer the lens, the more money it costs. I would recommend going to a skate park and shooting some photos with your present lens to see how much lens you need to get the subject a reasonable size in the frame. You might be able to go with a faster long lens if you don’t need the zoom range.
Depending on your level, you may have to stay outside in a spectator area or be allowed into the action area. I knew a drafter (engineering drawings) who also was a photographer and had a pass to be on the field for pro football games. Getting that type of authorization can move you much closer to the action which means that your lens can be much faster at a reasonable price.