I don't think that's largely a question of what's your need and goal. If you want programming as a hobby Python might a be better choice. If on the other hand you plan to do programming more seriously learning Nim is probably a better investment.
Reason for my opinion: Nim is a quite easy to learn language _for a serious system programming language_ plus it's very versatile; Nim covers "quick and dirty jobs" (that are typically done in Python or Ruby) and it allows also for, say, creating full servers (e.g. a web server). Python on the other hand is even easier to learn and has many more libraries, docu (incl. hundreds of websites about Python) and better tool support (like IDEs, editors and whatnot). It should be noted though that Nim being (not hard at all but) a bit harder to learn than Python is mainly due to what Nim is capable of and that Nim cares a lot about creating _good_ and _reliable_ software (which Python doesn't care about much). My personal opinion/advice is that you should stay at least a bit with Nim. If it turns out that you find it to be too hard or if you feel that you would need much more and better docu, or ... you can still switch to Python and lose nothing (and much of what you learn with Nim will stay valid and be helpful). It shouldn't take more than a few weeks (with an hour or so per day) playing with Nim to find out whether you and Nim get along well.
