Only invest what you can afford to lose. I think we all have something we can lose, but at different milestones it’s certainly very easy to invest too much.

Sometimes, in rare occasions you can get a small grant go dabble in investments, but don’t expect it.

Time is also an investment. How much are you losing by taking the class? If you have time to burn, there is nothing to lose, and having skills for events where you have money to lose is absolutely worth it

I of course don’t fully understand your financial situation. I believe there is an app called acorns that rounds your payments up and invests the extra cents. If you can spare that this could be a cheap and powerful introduction once you have taken the class