Hi all
Long time lurker first time poster so please go gentle.
Bit of an overview -
I split with dad of DD last year after a very long term relationship. I ended things as we'd grown apart and I had been unhappy for some time probably years but wasn't ready to end it until then. He was probably unhappy during the relationship too. Since then we've both moved on with life but still speak for DD.
Since then there has been a couple of very casual things with guys through friends of friends but none that went anywhere. I didn't make the first move which was nice as I wouldn't know where to start as I've been out of the dating game a long time.
A guy tried to add me on FB years and years ago but I declined as due to my job at that time I may have ended up dealing with him and his partner for work and it wouldn't have been appropriate as they'd have been 'clients'. Don't want to explain more in case I out myself. I'm not in that job anymore and haven't been for a few years.
Anyway a few weeks ago he added me on FB again and I accepted as work is no longer an issue since changing jobs. I live in a town where everyone knows everyone and we have mutual FB friends and RL acquaintances.
Since then he has posted lots of things which interest me, I think he's a good looking guy and I'd like to get to know him better. I've had a look stalk through his FB and I'm pretty sure he's single although it looks like him and DP got married and then divorced in 2017.
I'd like to message him and see ask if he'd like to get to know each other a bit better and then maybe meet for a drink or something to eat. I'd like to message a bit first as we really don't know anything about each other except what's out there on FB but I have no idea what to say.
Is it weird to message him directly through FB messenger now after 3 weeks?
I feel I should have done this when he first added me but I didn't know I was interested until recently when I've been seeing his posts. It's like that ship has sailed but would have been the perfect opener especially as he added me.
How would I start the conversation?
I've never had to make the first move and so I go to do it and then panic and chicken out. I feel like some silly school girl with a crush who's too shy to act on it 

What would you do?