What order should I learn meditation techniques in?

Breath focus first is the usual answer, because it is the simplest to describe and the technique most others assume. Body scan tends to come next, since having a clear next step makes it easier for anyone who finds the breath hard to stay with. Sound awareness, mantra and visualisation follow well once attention is steadier. In StillMind a Techniques course sequences this for you at the level you are at: a beginner course introduces one technique piece by piece, and a more advanced one takes the same practice toward whole-body breathing and choiceless awareness.