Can I go through security if I’m not flying? I want to se my son he will be 2 hours at the airport before his next fly, thank you

Of course, you are need exit and reenter for the security point, I have also seen relatives there, park correctly paying, and you see, he must return for the security point TSA

As a non traveller you can not enter past tsa as you need a valid boarding pass and passport. If your son exists the transit section then he can meet you in the airport building. Be advised that he will need to go thru tsa checks again. And it can sometimes take up to 45 minutes. So just be mindfull of the time