My individualized recipe is to ride away from home until you're tired, then ride back. That's a good ride. Endurance doesn't start until you start enduring. I started trying to ride the 5 miles uphill to a local shopping mall. Not because shopping, just to do it. Felt like I'd have bits of lung on my shoes. Once I could do that, I just kept going.
You can lower blood pressure cheaply and "naturally" by taking 1g of sodium nitrate every morning. The quotes because it is a natural process. Some folks drink beet juice to get their nitrate, but sodium nitrate is cheap and mostly tasteless.
https://www.amazon.com/Sodium-Nitrat...dp/B0190TOJUS/
It'll help your cycling a little, too.