Q: VPN

Why? Are you trying to access resources on a private network? Are you using someone else's unsecured WiFi network? If not, then there are very few (legal) reasons to use one.

A VPN is designed to allow you to access a private network, such as a corporate network. It creates a secure tunnel between your device and the network where the resources you want to use are. If you're not connecting to unknown, untrusted WiFi networks, there's no reason to be using a VPN for day to day use... Especially when the trustworthiness of the VPN providers is questionable to begin with.

VPN has basically two major purposes;

to provide you anonymity by hiding your IP and transferring your internet data through an encrypted tunnel so that no one can see your activities

it gives you the power to change your geographical location which helps you accessing geo-blocked websites

for safe and anonymous torrenting

if you have anyone these major purposes, then you can use a VPN