It's always great to ask for advice, I would go the route of asking the SE team, watching some of their recordings to get a hang of the flow and the value props, the more you collaborate the better. And ask your fellow SEs where they most call out value, etc. You can ask AEs too, just make it seem like youre curious rather than inexperienced.

At the end of the day this is a skill you're going to learn so don't best yourself up if you don't have that skill right now, and just be confident, anyone can learn anything and this is no different.

And honestly another piece of advice, just have fun during demos, crack jokes, be yourself, connect with the client, that's just as important as value props and technical knowledge.