Have him get involved with the local LGBT COMMUNITY CENTER. They always need volunteers!
PFLAG is a great organization for a family member. How and where you can be involved depends on where you live. I would start by googling your city and "LGBTQ"
Getting involved is as easy as to participate in social events from LGBT and find out from different organizations which one you would like to volunteer, participate or contribute on the state you are located. NY, NJ .etc Guidance for your grandson: you tube , now on days we have so much on the internet and is more open in society for everyone.it might help a local group or gay organization, friends.its always crucial to have someone that would listen in this case sounds it would be you and having someone to start our journey and discover, learn and new experiences with open mind not only will make it safer for your grandson but it will give you a different view of life. Also for him is always good counseling at a Hiv clinic on safe sex practices and tons of info on do's and don'ts Grandmoms with open minds can be angels from heaven as support system on youngsters lives
A good start will be to get connected to GLAAD or The Trevor Project. Both are organisations who provide support to the LGBTQIA++ community, it's allies and basically all those who need guidance and information about handling matters that involve the community.
Thanks! Your answer is awaiting moderation.