In terms of learning a new language, one of the easiest for English people to learn is German. As one of the biggest influences in the creation the English language, German still holds a lot of similarities, with us sharing many words, many more being very similar, and the flow of the language also sharing a lot of similarities.
If you want to learn a new language but the idea is quite intimidating, starting out with one of these ones is a great way to get your mind working, and still have a relatively easy time of it. Other easy languages which are worth checking out are; Dutch, French, Spanish (to a degree) and italtian (to a degree). The English language is basically a blend of Dutch, German, and French, with a few other influences. French is itself derived from Latin, as were Spanish and Italian, which is why other European languages tend to be more easily learned than languages from Asia or Africa.