Time. You need time to ride. And usually most people only have the time they make. Vary your rides throughout the week. Some hard, some easy. Some long some short. Don't rush to get gizmos unless it will motivate you more to get caught up in the numbers games. No matter what you make of the data they give you it still boils down to....... ride more! Though overtraining is a thing, but that's a later question to answer.

Besides that, take plenty of water with you. When you get to riding two to three or more hours, you might want to consider adding a carbohydrate mix and maybe some electrolytes to your water (salt will do).