I was raised a JW. I have found if you ask questions with a sincere tone of wanting to know the answers you will not get shut down as quickly.
My recommendation to you is to perhaps visit the library in the KH and look up some of the old literature such as the Finished Mystery Book. This was published around the time they said they were chosen by Jehovah to be the Faithful and Discreet Slave. Then you can ask your questions pertaining to your research such as what was it that happened in 1919 that definitively proves that they were chosen by Jehovah then and if he chose them then, why is it that what they believe now is so different to then?
If the question of you getting baptised comes up remind them that Jesus was 30 when he was baptised and that JW do not baptise children for the fact that they are not able to make such a life choice so young. It is a solemn and important decision that you do not want to rush into.
A few years ago we were told by a CO that until you are baptised, you are an unbeliever so all children and youths are technically unbelievers. (tell that to the kids who are refusing cake at school)
You are free to research and choose for yourself. If anyone pressures you remember that they say "we all must account for ourselves" so doing anything out of compulsion is not going to help anyone when Jehovah does the final judging.
At this stage - since you are not baptised - you are free to do all the research and learning you please and not just on the JW.org site. So go ahead and do the research. That is what the bible says to do in proverbs 14:5 and Romans 12: 1 & 2 and Acts 17:11.