(Concern) Skin laser effectiveness

I don't think I did this when I was young, but I have many freckles. I tend not to apply sunscreen properly. My facial structure has prominent cheekbones, so I have a lot of freckles on this side and I'm worried about it. I'm curious if skin laser treatments are definitely effective. It's not just a one-time treatment; it seems you need multiple sessions to see results, and the cost is also a concern. I have many blemishes here and there, and I want to get rid of all of them, but I'm worried about possible side effects.