Lara, these are pretty general questions so any of us can give answers! Coming out can be an awful experience, or some of the most wonderful feelings of your life. It depends on the people you come out to, and how you tell them you are trans. Most people associate trans with a sexual fetish, and will feel you are responsible for their uncomfortable freelinggs about this. I have found that by explaining to people that we have a medical condition caused in fetal development, they are much more accepting that we need treatment. It is far easier for people to accept a medical condition than a psychological one. 99% of the people I came out to this way have been amazingly supportive!
Starting HRT ususally means a significant reduction in genner dysphoria, that bad feeling that often comes and goes. Then, often a little frustration in the next couple of months as nothing seems to be happening. People will notice your skin softening, and comment that you look younger, even before you notice anything. When breast pain and development starts, a strong feeling of finally aligning with your gender identity begins, but those developing breasts can be quite painful and itchy!! You will notice a calmness, as stress slowly leaves you. Then you will likely enter a phase where things seem not to be happening fast enough! Natal puberty takes over 5 years and we also have to wait to complete ours, so HRT is a marathon, not a sprint!
I hope this helps some, and please, keep your questions coming. Know that there are others reading these posts who also have these questions but won't come on and post them, so you are helping others as you learn!
Hugs,
Allie