Just figure out what coin you want to exchange and look for a stable compatible wallet. As a rule, each coin has its official wallet client.
Note that each wallet has its unique address or a tag with a private key that is required to restore your wallet if you lose it. AjuBit will never asks for your private keys. Store them in a safe place and never show them to anyone. If your private keys are stolen, your wallet and all your coins will be lost forever.