What would you do?

So I've been working for Walmart since Feb 10 2015. It's been great so far up til hurricane Irma.
I haven't been able to do my own job because I've been doing thirds job. Which is stock the freight. I basically was behind weeks.
So I got punished for it.

I however got a job opportunity at a race track.
Working there would aid my schooling in a way to get my foot in the door with being a tech. No it won't be repairs but I will be somewhere with cars regardless. This will be til I finish school and start to get into garages and shops/dealers. Downside is. 27 hours a week but plenty of overtime opp. Lady that took my application told me they worked from 10am til 1am one day. For special drift events like these.

But also was told that if it rains I won't be working plus track only opened 4 days of the week. Thurs to sun. But like I said that totals to 27 hrs. Anyways I also have a friend at a pizza joint who can get me a job to work on the days off. So I will have some back up income from that.

Would you stay with Walmart or work at a race track? I'd like to have your honest opinion peeps. Thanks in advance!