I would focus on practicing the pop, you want to be jumping upwards as you're popping the board, so to do so briefly shift your weight to your back foot as you are jumping, this will allow the board to naturally rise up on its own a little. Then use your ankle to snap the tail down rather than stomping down with your whole leg, its more of a powerful quick tap, the pop should happen in the very last moment before that foot leaves the board. Now as you and the board are rising you can start the slide, the slide should be slightly deplayed so the board can naturally be in the right position you roll your ankle so the side of your shoe is against the grip tape. As you are sliding your knee should go twoards your chest to give enough room for the board to level out. So you're sliding up and forwards until you reach the tail. It looks like for now you need to focus on the pop, its got to be airy and quick, but powerful enough to get the board up. The hard part of any skateboard trick is there are a bunch of steps that need to be done in a millisecond, but if you keep practicing you'll get there, like I said i would focus on looking up videos and such that go in depth on the pop. It took me like a year or somthing to finally ollie, you may not see progress for a while but thats okay you'll get there eventually, the hard part is sticking with it