I was half-way through a long answer when it disappeared!
Main thrust was - there is nothing wrong at all in just praying quietly by oneself and sorting out one's relationship with God that way. :)
Churches are a bit different, you simply need to find one which suits you and your approach. We were lucky. I was Baptised C of E (and that's a broad church!!!) but was raised Methodist. OH has been in various incarnations of C of E (including The Church in Wales, which is its own ).
In France, the C of E had a huge parish (size of Wales) so hard to be a churchgoer. We have both been through (separately) life-changing events such as widowing, marital abuse and divorce. Somehow, God was always there for me - it turned out to be the same for OH after losing his beloved wife. We each got on with it quietly, like you.
We moved to our village in March this year. On Palm Sunday there was a procession from the village green to the local church (C of E) we joined in at the end. We have been made so welcome, it is hard to explain how comfortable and happy we both feel. C of E politics are not me and I often disagree with the statements from high-up, but locally is it us, a community of like-minded souls, building and working within the village.
Baptists and Methodists are offshoots of the C of E. I was baptised C of E, but raised Methodist (you are not supposed to drink alchohol if Methodist, but it's loosely applied in most places). Baptists do the 'total immersion' baptism (they have a portable tub). But it's not about bits like that, it's about where you feel comfortable talking to God.
However old you are, you are not too old! Honestly, just relax. If you wandered into our church on a Sunday you would be welcomed, given a cup of tea and a bun after the service, chatted to - and probably asked if you could sing and would like to join the choir!!! (We're a voice or two short.) :o)