It's either you make use of a centralized exchange as you've been told already if you don't mind about your privacy, but i will also recommend you with some available list of decentralized exchages from the thread link below, there are recommendations you could have from the list there.
but most importantly, whenever you acquired your bitcoin, always try to store them on personal wallet which are decentralized for your security and privacy, here are recommendations as well on wallet to store your bitcoin
Other recommendation on wallets for security and privacy if you care Bitcoin Core Passport