I followed advice from a friend's amazing nanny.
You go out twice a day every day, or once a day if you have visitors. Aim for at least one adult conversation every day.
Find playgroups, toddler's gym, swim, music, stories in library, NCT coffee morning, 1 o'clock club, soft play etc. Something each day to give structure to the week.
Then add a trip to the playpark or rec, or to the shops, health checks etc. We'd sometimes just go for a ride on a bus or a train as they love watching the world go by.
Don't feel at all guilty using TV as a nanny for an hour or so every afternoon. CBeebies goes on while you make dinner or have a cup of tea.
Encourage safe playtime alone - my DC loved water play. I'd fill the old baby bath with warm water and put it just outside the kitchen door so I could sort laundry or clean while he played. Looking back, I wish I'd done more of this. I felt I had to entertain my DC all the time and it was so exhausting. If I had that time again, I'd leave them to entertain themselves for a bit longer.
Play with him a bit - read a story or build a tower until it falls down or make teddy bears have silly conversations with him.