If you are going to “be your own bank” you need some very basic computer security skills like:
Research the reputation of the wallet you are going to use.
Don’t download wallets which aren’t open source
Download wallets from their official dev site, not some third party repo.
Don’t use Facebook search to find a wallet.
If you are storing significant funds, use a multi-sig wallet.
If you are not 100% confident in the security of a given wallet or system, send a smaller test transaction first before sending larger amounts
If you can’t be trusted to do that, you need to pick a trusted custodian to manage access to your funds (you know, like banks), preferably somebody who can get an insurance company to under-write your no-opsec-having-ass. Unfortunately, in the crypto world, these trusted custodians few and far between and have a terrible track record with exchange collapses etc. It’s getting better, but it’s still a mess. Hopefully as time goes on and the industry gets better regulated and more mature, this will be an easier thing to do.