Surfing Waves

so i recently bought a shortboard, even though i probably should have got a long board since ive never surfed before, but im stuck with what i have so im going to try and learn the hard way. ive gone 2 times and day one i practically couldnt catch a wave and day 2 i could catch a few but couldnt stand up. it seems like once im about to pop up the wave has either passed by or the board kinda sinks. i really dont think im too big for the board im 5'9 140 lbs and the board is 6'3 and i can sit up on it so it has to be something else. perhaps im not paddleing hard enough? so i have a few general questions that even after tedious research i havent quite understood... when do i start paddling to catch a wave? once i have caught the wave why cant i keep on after i attempt to pop up? does my back foot need to be on the grip pad or further up? thats all i can think of right now since i cant get up on the board yet. but id appreciate any help.

Nope, you are starting in the wrong place, a begginer does not start at the lineup.

Go out about to waist to chest high surf and wait for a nice moving whitewash come come your way. When it gets close to you throw yourself towads the shore with enough momentum to get the board going, then practice your popups. Do it over and over until you stand up more often than fall. If you can stand up 5 times in a row then you are ready for step two.

This will result in 3 things: 1) you will develop a smooth popup for when you can catch waves and 2) it will give you a better sence of balance on the board and 3) you will catch waves and fun right away. Yes you will look like a kook, cause you are one, so get your popup right first. Once you have your popup down you will get more comfortable with your board, which will help your paddling.

As to learning on a shortboard,the board is fine, it's easier to learn on a longboard, but many (even me) learned on shorter boards.

ok. basically i was jumping the gun tryin to walk before i crawl. i will be doing it your way next time. i appreciate it