I have an issue with the way the term "endurance" is used today. Most use it to simply refer to a road bike with a geometry that gives the rider a relaxed position or more upright position.

However if you are one that can ride a race fit or aggressive position with just as much comfort, then it won't really matter whether you look at race bikes or bikes for people that have to sit more upright and need a term to suggest they aren't impaired! <grin>

So if you have no experience with road bikes. Then I recommend that you go where you can try out the bikes and see what models seem to fit you the best, whether or not they are a race fit or relaxed fit. And don't spend much if you don't know for certain what type you are.

Longer rides will make a difference compared to shorter rides. That's where the term endurance comes in. But I can endure long rides with somewhat of a race fit bike. The question is, can you?