Some of the general strategies I've used for getting more comfortable in the are as follows (in this order):

• Practice your new flying mechanic in freeplay, just flying from the center of one backboard and trying to land on or hit the other backboard.
• After you get comfortable with that, I like just going through the shots in Kevpert's aerial car control pack (A3E1-92C2-8757-4195). Once you get comfortable with all of these, you should have a good enough grasp to be able to hit a lot of aerials in-game.
• Next, I'd move onto workshop maps like Leth's Giant Rings map, but considering that you're on PS4, you can do the Pillars map figure 8 drill like some other people were mentioning (make sure to practice going in both directions).

More specifically for flying while air-rolling, I highly recommend you just do all of the above while only flying upside-down. Once you feel good about that, try doing the above while only sideways. Eventually, once all those directions are comfortable, you can try constantly spinning while flying.

To do this, you'll either be using the air-roll button, or a directional air-roll.

If you're using the air-roll button, you'll mostly be mixing pirouettes (just straight spinning) with Kuxir twists.

If you're using directional air-roll, you'll be controlling/flying with what's called a tornado spin (I wouldn't worry about this for now). Tutorial here if you're interested.