As my irl self without fancy plot armor and being just as average as now?...

I will see that more realistic.
I would join the alchemy guild and learn there for a while.
When I know the basics of the world, I would start to create plastics.
Then start creating machines to get it into mass production.

As side hobby I would try to become a blackmage.
Then try to harvest energy from fire and lightning magic.

It is also useful because with ice magic I can cool down any room in the hot summer heat.