Backside and Frontside flips are a variation of the 180 Ollie and a kickflip. For a frontside kickflip you'll be doing a kickflip plus a frontisde 180 Ollie. To do that your finger positions should be the exact same as a regular kickflip, the only difference is when you go to pop the trick you want to kick your front finger out towards you rather than straight forward. This will not only do a kickflip but make the entire board flip towards you. Once you do the kickflip, you wanna catch it and continue the rotation with your entire arm until you reach a full 180 degrees. A nice way of learning this trick is to just do a regular kickflip, land it, then do a revert. From there you just do a kickflip and try to revert less and less until you can can kickflip and do entire 180 in the air. For backside kickflips you're doing the exact opposite: you're doing a kickflip but turning the board in the opposite direction. Like a backside 180. So to do that you have the exact same position as you would for a kickflip but to do that you turn your entire hand to the left, making your board spin away from you in the backside 180 motion. That's how you do the frontside and backside 180 kickflips.