I am new to crypto and everything I have done has been strictly through Coinbase. I don't have a key or anything like that.
Welcome to the crypto world. Coinbase is a good exchange but it's not that good to put all your capital in one place, try to make research about Gate exchange, Binance, KuCoin, Huobi too.
What can I do to make it safer?
First thing is to do not trust any crypto exchange, instead of having $1000 capital and trade all of it in Coinbase, you can split it into 2/3 of top exchanges similar to Coinbase (top exchanges). Always remember to use wallets (cold wallets) to store your coins for a long time. A cold wallet is good because your Bitcoin will be stored offline, that's why we called it a cold wallet. Make a research about Trezor wallet and Ledger.
Everyone talks about keys, what exactly is a key. Where can I purchase one and how does it work.
A key is the main security for your coins in wallets, it's like a Key to your house, a Key to your car, but the difference is if you lose a key to your crypto wallet then you will never recover it! So your money will be lost. Always remember to keep your wallet key somewhere safe (it's a digital key - a combination of numbers, letters, and special characters) so you can store it to your personal email, google drive, and so on.
Thanks and good luck to everyone. I am already up about 22 percent on my investment and extremely happy. I do feel that BTC will go to the moon.
Congratulations! 22% it's a very good profit because some staking pools will give you 7-10% yearly! Keep it up, Bitcoin is a good coin and the leading coin, it keeps growing day by day.