GrapheneOS a great private alternative Android, if you have a Pixel device although it of course has tradeoffs. I've been using Graphene for a year or two and love it. Although I got a new phone, the Pixel 10, and it's not yet available.
I've been using linux for a couple of decades, literally, and love it. Linux Mint is a great starting point.
Protonmail and their entire suite is fantastic. They now even have a word processor and spreadsheets similar to Google. Plus a VPN, password manager, calendar and drive.
LibreOffice is great, although not as refined as MS or Google.
I use PayPerQ (ppq.ai) for my AI queries. You pay with bitcoin and have access to most of the top models (it not all) and as the name implies, pay sats per question. Also more private since there are no accounts.