Hi AndyMase and welcome to the site.
If you’ve ridden bikes you will have a great understanding of what they can and should do so don’t worry about your lack of spanner experience your already half way there.
This is a pretty quiet site generally but it is full of help and knowledge. These 750 twins are about as basic as you can get so a great place to start learning hands on.
Whereabouts are you from?
With regards to your issues so far they seem quite normal.
Starter motor is a common fault and I would suggest deal with this last as it could get a little in depth.
The neutral light and high beam light not working is probably as simple as a blown bulb. That’s an easy fix. Unscrew and remove the round plastic nut around the ignition switch. The light cover can now be lifted off. Check the suspect lights to see if the bulbs have blown and replace as required. If you can’t tell if the bulbs have blown swap each one with one that works and see if that solves the problem.
Indicators not flashing unless revving the engine is down to tickover voltage. Hopefully for ease that’s a faulty battery but could be down to charging.
Exhaust blowing is obviously a leak. This could be due to a blown or missing exhaust gasket or maybe even as simple as a loose clamp nut. Try to tighten the nuts but don’t force them as we don’t want a snapped stud.