I think the usual steps I see are therapy, then seeing an endocronolgist who does bloodwork, then hormones, and then back to the therapist to get letters for surgery. However I've seen some guys start T before hormones. Surgery usually seems to come last.
For me it went: Therapy, then seeing a doctor who gave me hormones without bloodwork, then bloodwork in 3 months, and eventually I'll go back for surgery letter, then top surgery. Not sure about lower surgery yet.