Hi Michaelh,
Congrats on your first full shave!
Sounds like you didn't stop after doing your sideburn areas -very unwise!!
Stick to simple areas at first-I know it takes alot of self control,you feel inexplicably drawn to doing the rest of your face (I know cos I did the same!)-but the result will always be the same for the first 10/15 shaves until you get the "feel" of the razor-mainly cuts and nicks as you have discovered.
As other members have said -take it slow for these first shaves-your face is unique to you so take time to get to know the contours of it and how to shave them.The nicks and cuts gradually diminish and by the time you get to around 40/50 shaves they will become rare.
In the mean time allow your skin to heal.If you shave over a cut it will open up again,so give it 24 hours or so but continue to apply a good after shave balm to your skin especially on the damaged areas.
Use a D/E while you heal-somehow it does'nt open the cuts up like the straight does.
I think you will stick with it so I don't need to remind you.
Here's to many more shaves & may they be smooooth!!
Kind regards
Noggs