With three letter agency leaks showing us that everyone is being spied on, now more than ever people need privacy. Now if one of the three letter agencies have you on their watch list, I'm afraid it's probably to late. Those out there that are just looking for privacy though here's a guide.
Ditch anything Google, stop using chrome and use Firefox or Brave instead.
If you use Firefox, Install HTTPS everywhere and uBlock Origin. This will keep your traffic safe with HTTPS and uBlock will block trackers and ads.
Next stop using Google search and switch to Startpage or DuckDuckGo.
Make a Protonmail and use that, ditch gmail, yahoo, or w/e else isn't encrypted.
Next up is getting a VPN. A VPN will encrypt your traffic and make you more secure on public Wi-Fi, but it is NOT a all in one anonymity tool! It helps but it is not bulletproof and should not be thought as such.
If you want to go a step further, Install Tails on a USB stick and use that to browse when you absolutely want to be anonymous. Tails is your best bet at going anon. You could use something like Whonix, but I don't know if it is as secure as Tails.
EDIT: If you want me to explain how to set up any of these things, let me know and I will make a guide.