You will usually get tested for: FSH, LH, oestradiol, testosterone base levels. SHBG (sex hormone binding globulin) Thyroid function, B12, Liver function tests Cholesterol etc
The first set are baseline hormone levels. Once on Oestrogen (whatever form you get) testosterone will decrease, SHBG will increase, oestrodiol will increase. LFT can be/will be affected by being on oestrogen as this is where the sex hormones are metabolised. Thyroid function can be affected. Vitamin D levels will monitor how you can store calcium (remember once you have a female hormonal pattern you can get the female problems). Same with B12.
Endocrinologists vary, some wait to see what oestrogen does before they put you on anti androgens, some put you on them straight away. This is because if you put two endocrinologists in the same room they can't agree on how many endocrinologists are in the room.
Cindy