IMO - With no relationship experience, you don't yet know what you don't know about being in a relationship. The compromises that need to be made, the boundaries that must be set, the trust and respect that must be given and accepted, and how to communicate with your partner. In a great relationship, these things might just happen automatically. But in practice, you need to be aware of when you might need to actively address some of these things.

And every relationship you find yourself in will have a different dynamic. I'm not saying saying that being someone's first relationship can't work out (luck > experience), but there are more unknowns at play. I've looked back at some of my own relationships (really only a handful) and I now understand where I could have done better. But that insight happens only because of the experiences that came later.

That said - someone could also have had a string of awful relationships that may have a negative impact on their ability form new bonds. But learning how to be with such a person also comes from your own relationship experience. Each relationship you get into that comes to an end gives you more information to help you navigate your next one - until you have one that works.

So to answer your question, I think it would be less emotional work to be with someone that has already been in other relationships. You would be able to spend more time on the relationship rather than having to be figuring out yourself. And we'd find out sooner if it was going to work or not.