I think coding is probably the most valuable skill for contributing in depth to the steem project. It gives opportunities to contribute to existing projects, to build out your own ideas, and to better understand what the changes are that are being proposed in each hard fork.

As @tcpolymath points out above, it's worthwhile thinking about what your goals are and which of the above you want to do in making your choice of language.

Many of the dApps use javascript or one of the js libraries (react, vue, quasar etc). Steemit, busy, utopianv2, ulogs, steemhunt all fall into this category.

Steem itself is in C++.

Hivemind is in python and I think there's a huge amount of useful work that will be done here in the (hopefully near) future.

I don't think there's a right or wrong answer. It's also definitely worth popping in to the Utopian discord and chatting with the devs there to see what they think and meeting people on the same path.

Good luck!