Learning a foreign language for the first time? Start with Esperanto:
The results of these studies … demonstrated that studying Esperanto before another foreign language expedites the acquisition of the other, natural, language. This appears to be because learning subsequent foreign languages is easier than learning one’s first foreign language, whereas the use of a grammatically simple and culturally flexible auxiliary language like Esperanto lessens the first-language learning hurdle. In one study, a group of European secondary school students studied Esperanto for one year, then French for three years, and ended up with a significantly better command of French than a control group, who studied French for all four years.
I’m not sure we can extrapolate these findings cleanly to the learning of programming languages. Sure, learners of a new language encounter syntax issues, and there are some languages with simpler syntax than others. But are syntax issues the primary obstacle for those learning to program? If the bigger obstacles are algorithmic, the choice of a first language becomes less important.
Also, speaking and programming are very different activities. Could one year of Python and three years of Java produce a better Java programmer than one who used Java for four years?