How can I legally use VPN?

I'm curious to know, how can one legally utilize a VPN service? Are there any specific regulations or guidelines that need to be followed in order to ensure compliance with the law? Are there any countries or regions where using a VPN is restricted or prohibited? Additionally, are there any potential risks or consequences associated with using a VPN that I should be aware of? I'm looking for a clear and concise explanation that can help me navigate the legal landscape of VPN usage.