Morning chap,
Welcome to TGTT.
Generally you should start with maintenance to ensure the engine is a solid base to build on. Refresh the fluids and filters plus anything that you spot amiss.
From there it's time for breathing mods, handling improvements and increased braking. Once you are happy it'll take bigger power you can increase boost levels, upgrade the turbo and focus on engine management.
It can be a long road so don't rush in.
Jay