Any physical effects that are somewhat adverse as you first adjust - e.g. slight dizziness, nausea or hot flushes happen in the first couple of days and soon pass.
The speed of action of the AA depends on what you took........ some are really quick to act, some take a few weeks. Spontaneous erections stop happening thoughyou can still raise it by choice. It might take a month before you notice semen becoming less and more watery.
Psychological feelings from estrogen ....... probably begin to be noticeable by the second week and will ramp up over several months. They may peak about 6 months in with you being over-emotional for a while before settling down - there was a period where I couldn't watch a sad film or tell a sad bit of news without tearing up! It was embarrassing. But that recedes and you stabilize at a more balanced level, though still emotional and feminine in empathy.
Physically...... your boobs will probably be sore by the end of month one and the hard bumps of breast-buds forming under the nipple. The smell of your sweat will change too. The greasiness of skin and hair will also change in the first few weeks.
Of course, this is all personal to the individual and also depends on HRT types and dosages, so YMMV
