Something important to know is the difference between an actual sale (i.e. closing) and a sales process. If you want to be a good sales person, you focus on the sale, but if you are building a company, you need to figure out a sales process (which usually includes marketing on one end and onboarding on the other, not just sales).
It doesn't matter how good of a sales person you are if you are not getting any leads. Conversely, you can be a bad sales person, even with a bad product, but with enough leads, eventually they will buy - you can see this with crappy restaurants at airports for example.
Successful startups are very aware of this and they setup processes to generate enough leads so their sales people can close them, to generate their target revenue. Also, the sales person's responsibility is to close the people that "come through the door", but it shouldn't be their responsibility to bring those people in.
This is important and is largely what I wanted to add. At my company we have sales, who do the traditional listening to understand customer needs and working with them to build a deal that addresses those needs. But then we also have demand generation / sales development, focused on cold calling, getting leads, other marketing, etc, to get people through the door and you say. The OP needs to consider which of these (could be both) they want to build up their skills in. Reading about how to do sales will not help if you dont know how to get in front of people in the first place.
It doesn't matter how good of a sales person you are if you are not getting any leads. Conversely, you can be a bad sales person, even with a bad product, but with enough leads, eventually they will buy - you can see this with crappy restaurants at airports for example.
Successful startups are very aware of this and they setup processes to generate enough leads so their sales people can close them, to generate their target revenue. Also, the sales person's responsibility is to close the people that "come through the door", but it shouldn't be their responsibility to bring those people in.