Great to see the project coming together!
A shipping container.. maybe review this thread and the pictures of a truck inside one. Storage maybe but you could not work on it
https://67-72chevytrucks.com/vboard/...d.php?t=506825
Humidity is a killer around here using one for household storage, I understand a way to make it work is spray foam, vents and a 24/7 100 watt incandescent bulb. Most municipalities around BC have bylaws about using one for storage in residential areas.
Consider getting a carport tent frame off marketplace free or cheap and covering it with 14 mil poly. Put it alongside a building for wind protection.
for longer lasting, build a 'bow frame' shed covered with poly from 1x lumber, you can nail the poly down which makes that a better option than the steel tube frame, just more work.
A buddy built a sailboat under a simple gable roof frame covered in black poly with lath nailed on top of poly to hold it down, it lasted a good 10 years and as a clearly temporary structure withstood several visits from bylaw officers. I have had my parents old boatshed roof covered with poly for at least 10 years now.