Which language do you think/know would be the easiest to learn from the choices given? French, German, Spanish, or Japanese

I would also recommend choosing something you will be around. It is easier to learn a language if you can find a place to apply it.

I can tell you which is the hardest for an English speaker, Japanese.

French and Spanish are from the same family and similar in many ways.

German is the closet to English, but Spanish probably will have the most practical use in the United States for the foreseeable future. Not trying to profile but PVT Angelo Velez, you may want to at least consider Spanish.

My wife teaches French and Spanish. I find that they're equally difficult. Spanish has many tenses , but French pronunciation is harder. Japanese is hard because of its micrograms / alphabet. From my own experience German is the easier.