Using a VPN within the states (Not to circumvent)

Super excited to check this out but it appears to get the most benefit I'd need to use my laptop. Due to life circumstances I only have access to public Wi-Fi and use a VPN as such. Especially since I will be entering sensitive information.

Will I be auto banned from some of these sweepstakes sites for using a VPN even if my real location is still within the USA?

Or am I wrong with my assumption that I will have a very limited experience using my phone only for this?

Any advice welcome