A simple trade currency

Hello I’m new to Monero and mainly I’m just looking to do like a type of conversion currency.
Reason to why is cause there’s individual who prefer nothing but cryptocurrency. I understand them I mainly prefer cash as payment than anything.
Basically I just want to convert 10 to 20 USD to XMR (i think it what it use mainly). Just to pay someone who use this only.

I just want to convert my money to be use at the moment when needed.

Why do you create a thread here? There are probably many payment methods and sellers available for that.