How do I find a position in world space given an initial position, distance, and rotation?

I am trying to set up a bodyPosition so my player moves to the direct left or right of the camera's orientation when a button is pressed. I think I may need some trigonometry, but I'm not fully sure. I don't have the best recollection of my linear algebra classes, so i'm wondering if someone can push me in the right direction (I don't work with math a lot so I honestly don't know what im doing).

What I Currently Have:

• the camera's Y rotation (in radians, if i should change it to degrees lemme know)

• the distance the player would travel

What I Need:

• the end position

local function yOrientation(obj)
	if obj then
		local cframe = obj:ToWorldSpace()
		local x,y,z = cframe.Angles
		
		return y
	else
		return nil
	end
end

function physics:LinearThrust(forceType,D,P,maxForce,distance,camCFrame)
	print("thrusting!")
	if forceType == "BodyPosition" then
		local initPosition = self.hrp.Position -- returns vector3
		local rotation = yOrientation(camCFrame) or yOrientation(self.hrp) -- returns radian relative to world space
		
		local thrust = Instance.new("BodyPosition")
		thrust.Parent = self.hrp
		thrust.D = D
		thrust.MaxForce = Vector3.new(maxForce,maxForce,maxForce)
		thrust.P = P
		
		-- with initial position and rotation, you need to find the end position
		
	end
end