Proton VPN is the VPN from the same Swiss group as Proton Mail. The apps are open source. The free tier uses the same no-logs rule as the paid one, which is rare and also slow and limited to a few countries. Paid plans add Secure Core hops and more locations. They publish audits.
Swiss law still has courts. A VPN that keeps no traffic logs cannot hand over a traffic log. It can still be asked about payment records if you paid by card in your own name. The apps will suggest the rest of Proton. That bundle is convenient and it is also one company holding mail, VPN, drive, and passwords.
Use the free tier to see if you hate VPNs. Pay if you actually need a country that is not on the free list. protonvpn.com
Proton VPN’s free tier is a real VPN with a short country list, not an ad injector. Speeds will annoy you. That is how the paid plan sells itself. Secure Core, on paid plans, enters through a safer country first. It is slower. Use it when the threat is the network you are on, not when you are downloading a disk image. The same Proton login ties the VPN to your mail if you use one account for both.