I have been working with software development since I was a junior in high school. I have used at least twenty-five languages for various projects. I can take my coding skills from language to language (at least in groups of languages). What type of development would you like to do? The answer to that question will determine what practices you need to develop for your coding skills. Once you know that, then it is wise to choose a language that will help you develop those skills. Learning how to code goes hand-in-hand with learning a particular language. Unless you want to do legacy programming (FORTRAN, Assembler/Assembly, or COBOL), I would suggest learning structure programming/coding language like C, Algol, Ada, or Pascal. C seems to be the most common language in this group. These languages would be good for learning basic coding skills. For more advanced skills, I would recommend an Object Oriented language. The language with which I started was SmallTalk, which is not that commonly used anymore. Other languages include C++ for a compiled-to-a-specific-architecture language, Java for a language that compiles to run on a virtual machine, or Python if you want to learn an interpreted language. Java would be good for you to learn coding for mobile phones. If you are doing work on Microsoft platforms, then C# would be the language to use.
Almost a totally different mindset is needed if you plan to do string manipulation and searches. Some of the languages listed above would do well, but there are languages specifically designed for this. Two that I have used are Snobol and Prolog. Prolog (SWI-Prolog) is a much more modern language than Snobol (SNOBOL4 Resources), but both have their place.
As a side note, the language with which I had the most fun was LISP, it has since evolved into Common LISP (Welcome to Common-Lisp.net!). It is just as old of language as FORTRAN and COBOL. but totally different. In fact, it will warp your coding techniques and think in ways that you may never have thought before.
Bottom line, learning good coding techniques and learning a specific language go hand-in-hand. Some basic coding techniques are true no matter what language you are using and will serve you well in all languages. Other coding techniques have developed around a group of languages, like Object Oriented Programming. Good luck in whatever you choose to do.