One of the bits of advice I give any newbie is keep your leg together, splaying them out to either side to act as outriggers disrupts your balance and if you have to kick it is really important to get a rhythm that works with your paddle strokes or it will unbalance you.
get your arm work strong and even, that's more important than kicking. There are other things you can do on a short board for later takeoffs like the submerging board popping out paddle. The no stroke pop up and drop takeoff.
Let's just make you aware that even after 50 years of surfing there are new things I am still learning.
Kicking on a longboard is a bit like our nunchuk friend

I've taken up troll hunting just for fun, instead of a rifle I'll just use a pun! 冲浪爷爷