Without a doubt, don't waste your time on anything other than air-gapped hardware wallets, because if you're serious, then you need serious things that provide maximum security if you set them up the right way. After that, it all depends on how you save your backup (seed, private keys) and whether you keep your mouth shut and don't talk about investing in Bitcoin to the people around you.
Privacy matters a lot and to gain privacy, the best way is keeping your mouth shut off and don't let anyone lnow that you are a Bitcoin investor and have bitcoin stored somewhere.
They will naturally be cautious about how many bitcoin you have and where you store your bitcoins. With bad and immoral people, they will figure out how to steal your bitcoins including vigorous ways that can harm you and even your life.
More advice on privacy.
Bitcoin Privacy Information.