playerForward = {cos(playerAngle +90 ), 0, sin(playerAngle +90 )}

For example.

For this I'll assume you have a vector to describe the player position as opposed to separate x, y and z variables.

// You might also want something to adjust the angle the player is facing, for example the right stick X axis:
playerAngle += c.rx

playerForward = {cos(playerAngle), 0, sin(playerAngle)} // 0 on the Y axis assuming you don't want to fly around but move on the ground.
playerPos += playerFoward * c.ly // Add the player forward vector to player position, using the controller Y axis value as a modifier.

You will likely need to modify the controller variables (.ly/.rx etc) to make the numbers move nicely in your project, depending on the scale of things and such. Usually multiplying them by zero point something is a good place to start.

To get the side vector, we can take the cross product of the player forward vector and the pure Y axis. This would give us left and right movement, mapped to something like the left stick X axis this creates complete movement!

playerSide = cross(playerForward, {0, 1, 0})
playerPos += playerSide * c.lx

Apologies if it's more info than needed, but just wanted to make sure you had this to refer to if you require it!

Assuming a fixed camera, and if I’m remembering correctly, If you do something like

Player.x += sin(player.angle)*c.ly
Player.z += cos(player.angle)*c.ly

That should at least give you an idea to get you started...