When it freezes does the screen stay on?
Or does the laptop stop doing what it was AND switch itself off?
Any error messages that come up?
Is it just certain applications that freeze? Whilst you can run others OK?
Are you running Windows on it?
If you open file explorer and right click on the c: drive and left click properties, what's it showing for disk space used and free?
Does your laptop have built in diagnostics (you have to interupt the power on sequence and select the diagnostic option) If so what happens when run these?
This is all the sort of thing that would be easy to diagnose and probably cheap and easy to fix by a competent technician. But is tricky to resolve via user description on a forum.