Soft plays do have baby areas.
Can deffo do finger paints.
I went to a baby class at my local church at that age, think it was like £1, you get a coffee and biscuit, babies play together. See if there's anything like that round your area.
Library.
Plenty of walks.
In the garden, know it's cold at the minute but on warmer days, blanket down, wrapped up, toys out and some bubbles.
Local cafe for coffee and cake!
Towel on floor, pans, utensils, water, pasta and rice. Let him explore it.
Kenetic sand, slime for some sensory.
Disco light and music on.
Look on Pinterest!
Your doing absolutely fine. I had plenty of chill days when my son was little.