Hi Mussie,
I cant guarantee that you wont get anxious, but I can tell you that travelling with a group like JY is a safe and fun way to travel. There is always someone to hang around with, share a meal with and share the holiday with. At 60 you are definitely not too old. Ages range from 30's to 80's, everyone mixes and most look out for each other. You will soon make some new friends to share experiences with.
You can join in as much or as little as you like on the holiday. You don't have to do all the trips, but if you change your mind and decide you want to, your tour manager can help you.
I say take the plunge and book your first holiday... but be warned, travelling this way is addictive!!
Good Luck
Kezzer