Hello, in this guide you can see the list of all the tricks you can do in game and what their respective keys are to activate them.
Although before getting into the tricks you need to master how to gain enough speed to do bigger jumps and have more airtime for more tricks.
The button to accelerate is Space although landing is also crucial, if you don't land correctly and in the right timing you won't have much space to accelerate and do the next jump. So as soon as you reach your maximum jump height and you are starting to come down you need to align yourself with the ramp to land on the start of it (not in the middle) and start pressing space so you fall faster and you will see wind coming out of you. This is very important that you start to accelerate on your downfall into the ramp since it will gain a lot of momentum. Don't try to do a last trick since that can really screw your speed.

See in the picture below how I am already aligning to the ramp and already speeding down with the wind behind me so that I enter the ramp full speed.

Just press the keys below each trick name to make it.



Table:
W

Superman:
W + A

BarSpin:
A

Toboggan
S + A

Old School:
W + D

TailWhip:
D

Can-can:
S + D

Turndown:
S

One Hand Table
Left Shift/Right Shift + W

Cliffhanger
Left Shift/Right Shift + W + A

Bikeflip
Left Shift/Right Shift + A

X-up
Left Shift/Right Shift + S + A

Suicide
Left Shift/Right Shift + W + D

Decade
Left Shift/Right Shift + D

No foot can-can
Left Shift/Right Shift + S + D

Kickout
Left Shift/Right Shift + S

Manual
Land just with your backwheel and keep going like that

Nose Manual
Land just with your frontwheel and keep going like that

50-50
Land with both wheels on a rail.

Icepick
Land with just your backwheel on a rail.

Toothpick
Land with just your frontwheel on a rail.

360/720/1080/1440 Spins
Just tap the up arrow or the down arrow to do a 360 spin, if you keep holding it it will increase to 720, 1080, 1440 spins.
This can be combined with the Simple Tricks, Advanced Tricks and/or Flips by doing them simultaneously.

Frontflip
Hold the right arrow

Backflip
Hold the left arrow

These can be combined with any of the simple tricks, advanced tricks and/or spins.

To repeat a trick just keep holding the trick key to keep going for a double, triple, quad or insane trick.
For example if you want to do a barspin just keep holding A, it will start as Barspin then will change to Double Barspin, Triple Barspin, Quad Barspin, Insane Barspin.

If the trick is a combination of 2 keys then holding it will just keep the position while you accumulate points.
For example if you do the trick Superman it will keep in that pose for as long as you hold the keys.

Hope this helps, I was a bit stuck at first when started the game without knowing how to gain speed and forgot some of the trick names in the tutorial but here they are and let me know if you found any issues with this guide. Have fun doing some cool tricks.