PBs since age 60: 5k- 24:36, 10k - 47:17. Half Marathon- 1:42:41.
10 miles (unofficial) 1:16:44.
Marquess of Utopia
I like Joe's suggestion for at least a few weeks. As far as your racing schedule goes, I would go with the De Russey 5k at week 4. Give it your best effort, which doesn't mean killing yourself in the first mile (like I often do), and use that race as benchmark for basing training paces on going forward. Gradually increasing mileage to where you can run in 40's week after week would help a lot too.
Welcome, and keep posting