Yes, you should use the occupation that you did the majority of the year which appears to be "unemployed".
The other options that could be used are:
- the occupation on your return that you eventually acquired in January 2021 while you are preparing your return
- "Clerk" could also be used since you did that the beginning of last year.
Generally the stock trading would not be considered your occupation because it would generate investment income instead of work income since that is not what you do for a living),
Any of them would be fine except the stock trader