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.