Are you looking to date again, or just wanting to do more stuff with friends?
I've actually reconnected with a few old school friends since being single - people I still kept loosely in touch with on Facebook but hadn't actually seen in decades. It took a bit of courage to suggest a meeting, but generally I think most people are really pleased to get a invitation to go for drinks or a coffee - I'm a similar age to you and I think a lot of us are now feeling a little....isolated? Too strong a word maybe but I am not sure what the right one is. Including women who are still with their partners - a lot of us feel like we have got out of the habit of going out, socialising.
I also take myself out sometimes, whether that's to the cinema, to the pub with a book, or to look round a nice local town maybe? Or take a book and a drink to the park now the weather is getting nicer.
At home I read loads, do a few easy crafts, bake sometimes. When I was first single I was a little depressed I think, and did a lot of jigsaws - my brother's counsellor told him they are good for anxiety and depression, and I found that really true!
I also got a cat, who is great company.
And I take one of my elderly relatives, who is quite vulnerable, out for coffee every month or so. I very rarely used to have the tone before. She says it's made her feel a lot better about her life, and I feel good that I am helping someone else feel good.
My mom is recently widowed and I also try to spend time with her regularly......
If I think of anything else I will let you know. The main thing is, be kind to yourself. It's understandable to feel lonely sometimes - be your own best friend and treat yourself with gentleness and care.