I'd highly recommend proton vpn, I use it personally for my phone.
the only downside is that it's one device per free account, but alts negate that.
They have dedicated free servers that usually say they are full (and I don't doubt that), but I've never experienced any sort of speed limitations. Then again, I only ever look at Twitter or Instagram through it.
if you want a paid VPN surfshark and PIA are really good, should you decide on paying of course.
I have used both personally.
hope this helps