Learn GPG now or else you will lose all capacity for privacy.
You want real comp security? Learn how to use GNU/Linux else you'll never see it again, digitally.
Get your phone off goggle & fApple too. You need an explination? AI. If you think that's not an explination then ask Arnold S. Do I really need to include his ridiculously famous last name too? I've already said way too much why. Anyway, learn to smoke your mini mobile box with LineageOS on most devices. If you want the better, then GrapheneOS or CalyxOS. Limited kinds of phones for installation viable though. You want the best option currently available? Librem 5 from Puri.sm
Learn FOSS and in particular, the Philosophy. Trust no ONE ever with regards to software and hardware. Trust the masses if you can't read check the signatures and the verifications. Else scroll the books of instructions to trust yourself.
All that is hence GPG. Not only is it private messages but it's also the ability to sign shit, digitally, for real. Not the stupid corporate websites where you click it after agreeing to shit you didn't fucking read anyway.