Gym class zero.

How do I get better in gym calss. Like I cannot even barely lift meself off the floor for 10 secnods, I cannot even do a push UP I can just go down easy LOL but seriously.

imyselfandme is right . If you eat the right kind of food (no junk) you will be able to do pushups all day long.

Haha, from the title I thought you were making fun of the band Gym Class Hero.
Just start working out on your own. Maybe go to a local gym. Just start doing push ups and sit-ups at night or when you wake up in the morning. You don't even have to do that many, just make sure you do them consistently every day. Also, if you eat badly that can affect a lot. Try picking your food more carefully.

good luck!

eat healthy and work out daily

You have to start somewhere and you will be hurtin for the first few times of doing situps and pushups but every day do a few more. Eventually you will get better.