If you have trouble with tenses, plurals, and building sentences but you can learn other alphabets/texts and don’t have trouble with non-Western pronunciations, I would suggest Mandarin. I’ve been told it looks great on your resume, and the sentence structure is almost identical to English. There are no tenses or plurals to worry about–in Mandarin you just have a verb and if it already happened there’s a suffix. You will have to learn a new writing system and the fact that it is tonal gives some people (like me) trouble, but if you really get excited about it, it’s a great language to know. Plus you’ll probably be exposed to recent Chinese history and culture, which is fascinating.