I suggest to use mobile bitcoin wallet like mycelium or blockchain wallet. These wallets are good for holding and spending little amount of bitcoin.
MyCelium is okay for Android. Please don't use Blockchain.com's wallet. They have a bad track record of being competent in managing their user's funds and have been involved in quite a few blunders. If history is any indication, I can't recommend Blockchain wallet with their terrible fees estimation and deceptive user's freedom.
download a hardware wallet in a storage device. These are what we called as cold wallets where btc stored offline. Correct me if I am wrong because I am still new in cryptocurrency.
Hardware wallets are devices designed specifically to store Bitcoins and they cannot be downloaded. If you want to store Bitcoin, you're looking at a Bitcoin cold storage. It'll be better to have an airgapped wallet than simply a cold storage though.