Should I try to sell on the first call?

Slow down, the first call has a different job. Its purpose is rapport, understanding, and fit, in that order. Who is this person? What do they actually want? Does what you offer genuinely help them? You cannot answer any of that while pitching. So ask, listen, and take notes. If fit is obvious and they are eager, sure, keep going. But most sales are lost by presenting too early, not too late. People buy from those who understand them. Understanding comes first. Always.