They're all somewhat similar logically and whatnot, but have different syntax rules and stuff. So once you know one it will be much easier to learn another. Although it gets easy to mix them up once you know a few, in my opinion
However you need to make sure that you don't get into bad habits now.
Firstly, do not learn C++ or Java as your first languages. You will not learn to program well.
However, you must not learn something like Visual Basic or any of the .NETs. This is simply because they'll get you into thinking the wrong way.
Also think about if you wish to go to university to study Computing or Computer Science. I am aiming for Cambridge or Durham and they both say that you ought not to learn the languages they teach you beforehand - or any other language like it. So if this is even the tiniest possibility then don't learn C++ or Java - and neither should be a first language.
One thing to note about python is you should always end a line with a ";". This is not necessary, but it will get you in to good habits. Moving from a Python with no ";"s to PHP or Pascal which need them is horrible.