Both Django and web2py are excellent 'full stack' web frameworks with similar features and capabilities - you won't be 'missing out' on much as a beginner with either framework.
It's hard to answer your question without knowing more about what you want to do with your learning. Some would say that there is a danger of learning the framework and not the language so it might be best to get a deeper understanding of the Python language and lighter weight frameworks (e.g. Flask or wekzeug) first.
Having said that, web2py has a lower initial learning curve than Django as it was specifically designed as a learning tool. So I'd say you've made a good choice. No learning is ever wasted and if you decided you need something else in the future the good techniques you will have learnt using web2py will not go to waste.
Although there are more learning resources for Django, as it has been around longer and has more users, learning web2py is also fast because of the excellent book and almost instant responses to questions on the user group.
If you're looking to get a job, there are more Django jobs so that might be a factor. Having said that, the web2py community has recently set up experts4solutions where you could promote your skills and availability in the future.
Have fun!
