I know that proxy questions get asked a lot and I did do a search, but I couldn't find exactly what I was looking for. So I am humbly asking for some help with proxies.

The thing is that I am buying a really epic main + sides, I want this to become my permanent main, but I have a little problem.
Around the 14th I changed my Internet provider and got a new router, so I would think that means that, I also got a new IP, however I logged into another account, a couple of times I think, so my IP might actually be connected to that account.

I don't want to risk this new account, so I think I need to use a proxy, but I have never used proxies before, except that Hide My Ass free one, that you can add to FF. However it loads sites really weird, so I stopped using it and I didn't use it for Neo at all, I wanted to watch a YouTube video that was restricted to specific regions.

My questions are:
Do I need to use a proxy/is my IP connected to that account I logged in on?
And where can I buy a private, high security/elite proxy that is also high speed?

I have heard something about VPN's, but I don't know what they are and also it's important to me, that they are private as I have heard several times on the forum that, if someone else used the same proxy and they got frozen, you could get frozen as well.

I will really appreciate any advise you can give