I plan to use Monero to receive donations. In case of whatever reason something goes wrong with my laptop, I wan't to be able to keep back ups of my funds. Is this possible? I have an Android phone and an external drive. How do I go about backing up Monero funds from my Windows laptop to my phone and/or external drive?
Your funds are not stored on your laptop, they're stored on the blockchain. Copies of the blockchain are stored on perhaps hundreds of thousands of computers all over the world.
What you need to keep safe is your Monero seed. This is the credential that you use to scan the blockchain to see what funds have been sent to you, and to prove you have the right to spend those funds.
If you keep your seed (the 25 word phrase) safe, then even if your laptop breaks, you can at any point in the future download and install a fresh copy of the Monero wallet software on another computer and have full access to view and spend your funds.
If you are using your wallet to send funds to people, your wallet file on the computer you are using will build up a log of your outgoing transactions. Because of Monero's privacy mechanisms, if you lose access to the wallet file, then you can't later figure out the Monero wallet addresses of people you've paid. All that will be remembered is that you did make outgoing payments on particular dates.
On Windows, your wallets are typically stored in your Documents\Monero\wallets folder.
On Mac, your wallets are typically stored in the monero\wallets folder.
Therefore for full access to view and spend your funds, you only need to keep a safe copy of your 25 word seed. But to also remember your outgoing transaction history, you'll also want to keep regular backups of the wallet file on the computer you use to make those transactions.