bitcoin noob but here goes. I have a bitcoin address (obviously) and someone has sent me bitcoins. Now I don't have a wallet just the address (public and private) in order to withdraw from an ATM or maybe even purchase stuff? Do I have to create a bitcoin wallet as well? Sorry if that is a REALLY dumb question but I don't know too much about this stuff. Thanks guys
By having the private key you can sweep the wallet using a desktop or mobile wallet, I recommend electrum.
If you are new to the bitcoin world, visit https://bitcoin.org that has a lot of information so you can get up to date and get out of duduas
You're just puzzling your self.
If you want to send your Bitcoin to someone or buying some product. You will need a Bitcoin wallet or you can sweep that address funds to the destination address using e.g. electrum..
I don't much about exchange or how to withdraw your bitcoin from an "ATM" but you have to check localbitcoins.com, they can exchange your bitcoins based on your country.
Get a wallet and import your privkey