Learning Multiple Languages Simultaneously
Would it be counterproductive to attempt to learn multiple languages at the same time?
It depends on what languages you are aiming at, but generally, I would advise against it. If you are looking into web development, you are eventually going to use multiple languages at once (i.e JavaScript, Ruby, PHP, etc). Learning multiple languages simultaneously may cause you to feel confused and mix up the syntaxes sometimes; however, it can also strengthen your linguistic abilities, making you able to solve problems better. On the other hand, it will take longer to become good at one specific language.
If you insist, choose languages of similar structure and syntax, such as Java and C#.