Hi there and welcome here. You will get much honest information here. Bottom line is, being curious is not a bad thing. Just guard your heart. The JW's are a cult-like organization and very strict and dogmatic. From the outside it appears "too good to be true". It is. There are many serious flaws in their belief system and the way they live their lives, many shunning family members completely--just because they choose a different path later on.
No doubt this gentleman friend of yours presents a nice package, but even with his interest in you, he is living on the edge of their doctrines. Depending upon how tied up he is in it, and his family, will depend upon how secure your relationship will be since you are an outsider. Studying with them is not a bad thing, if you are just seeking information about them; but it is never that simple in their strategic plans for newcomers. They will latch onto you and pull you in. Free will comes to mind here, and if I were you, I would RUN to the nearest exit and not go back.
What happens to most sincere people, attempting to find joy and happiness and acceptance in a religious group situation, they are brought in and giving all the love and attention in the world. They make you feel so loved and welcome. They push for bible study and baptism--you are included in most everything, with promises to be included and made a part of everything, ONCE you are baptized; and then BAM, they've got you. The web has been spun, and you are that little innocent butterfly that ventured too close, got caught in the web and will be devoured. You will lose yourself quickly, as none of what you "think" matters anymore. It is the organization that will dictate your every move, and watchful eyes that will catch you in your weaknesses.
I've been there. You can check my posting history since I put my first thread on here in June of '02. It is your choice, and no one can make it for you. Be very careful! It can take a big chunk out of your life and change you forever.