Tier 2 visa-2nd job-start a charity organization

[qin]

i am working as a mandarin teacher in a school under Tier 2 visa. Another Mandarin language centre asked me if i can do part-time mandarin teacher at weekend. Can I say "YES' to it?

According to https://www.gov.uk/tier-2-general/overview, it is written that 'do a second job in the same sector and at the same level as your main job for up to 20 hours per week'

Can the part-time job counted as a second job in the same sector and at the same level as my main job?

I need a platform to try my entrepreneur idea freely at my spare time. However, I was told that I cannot start a company, in this case, can I start a charity organization?

[Wanderer]

AIUI, so long as it's PAYE it's fine.