What do you use to hold curls???

I have finally nailed beachy waves using a hair straightener, and I'm soo happy about it because I can't even figure out a curler and I'm 22 😅

So now the problem is, how do I get them to stay? I have naturally straight/wavy hair, it's pretty healthy, soft and blonde/brunette, after an hour or so, most of the curls/waves drop, I asked my mom what to use and she said hairspray but I don't want my hair sticky or looking crunchy, I want it to look natural if that makes sense, flowy?

Right now I don't use any products in my hair at all, I just wash and air dry it.

Any suggestions or advice appreciated as I am pretty clueless when it comes to hair, there sooo many products out there 😅☺️

The picture is very similar to my hair right now, mines just more drier