Starting T (Crossposted to /r/ftm)

(Sorry for the wall of text - I figured I'd put everything in one post instead of a bunch of separate ones)

I'm 18 years old, have been living full time as male for a while, and will finally be in the financial/social/legal position of being able to start T in the next few month (I have a letter for it, I just need to find a doctor / get an appointment / murder my parents). I have obviously read a lot about the effects, but I still have a few questions.

1. Working out. I'm pretty weak right now, but would like to get some more muscle. Is there any sort of a noticeable advantage to starting now, as opposed to starting to work out more once I'm on T? I don't want to waste my time (I spent all last year working out multiple times a week yet somehow seemed to gain no muscle), but I don't know if it will be easier to gain new muscle if I already have some.

2. Time. I know most things take a while to happen, and it's all a gradual process. However, how long will it be before I start to notice ANY effects? Will I see anything the first week? What about the first month? How long until other people would notice something?

3. I've heard conflicting reports on whether or not T is bad for your liver - the internet seems to say that since it's an injection it isn't, but my therapist (who isn't a doctor) said it is. I'm (as far as I know) healthy right now, but should I cut back on my alcohol consumption when I start?

4. I haven't found anything about the effect of T on sleep - does anyone have any first hand experience with insomnia? Could it make it worse? On an only vaguely related note, has anyone noticed a difference in ADHD? Could it make my medication less effective?

5. Anything else I should know? Any tips? Things to try? Things to avoid? Things you wish you knew before starting?