Some simple things to look into:

• Change your DNS resolver on all devices to something privacy friendly
• Use a search engine with less tracking
• Ublock, Privacy Badger etc for browser extensions
• Firefox with disabled tracking (look into forks like Librewolf)
• Change your keyboard on your phone to something local with no tracking (FUTO Keyboard)
• This for Windows, just use normal settings if you dont know what you’re doing
• Install Fdroid for open source apps. Many privacy friendly options.
• Look into how to disable telemitry on all the devices you use. Some of the above will already help you with that.

And in general, try to use services from the EU, as its privacy laws are much stronger than other alternatives.

Good luck, let me know if you need something more advanced.