If I were to make a poster for a school event, for example, prom and I use a font, Is it considered personal use since I won't be making money of it? Thank you in advance

Like always, the best thing to do to be absolutely sure is to contact the author.

oh okay thank you!

I'm pretty sure that the author will not be present at your even in a Philippines School. So, the risk is minimal...

Unless that is my font and I happen to be at that Philippines school.

To make clear what toto means, a poster - or whatever - for a school event is not private use but public use. The fact that you do not make any money out of it is irrelevant. Private is by yourself for (only) yourself. Which is not the case.
The Kat keeps wondering why people with as it seems a resonable education which should be perfectly able to understand the meaning of personal still try to find ways to cheat.