I enjoy singing for fun, and I'm really struggling to find my head voice. I've never been told what my voice type is, but if I had to guess I'd say I'm likely a baritone. As the title states, I'm wondering if you have any tips on finding my head voice. When I try doing anything high it sounds like a super airy falsetto, and that's obviously not what I'm trying to do. Any advice is appreciated.

-Oh, I understand lessons are my best bet, but I'm a college student and can't afford any right now. :/
Narrow your vowels and add pharyngeal resonance (that probably means nothing for you though). Generally if you are actually in head voice, you can increase the volume quite a lot with ease (to the same level as chest voice), whereas in falsetto you cannot increase the volume by much. There is also a ringing quality to it, at least for me.
To actually learn the pharyngeal function if you don't naturally have it, I would recommend the "Ba" sound/vowel. It's the perfect sound for learning it. How you use your pharyngeal voice after you learn it, is a completey different deal.