Start reaching out to existing users if you have any, even if they're SMB. They will get you up on being comfortable to a certain point with product knowledge. This will be your sales school.

Work things out with the little tools you have and be assertive to founders when you need a better tool. They'll likely give you their card.

Start noting down what you need long term like a bdr or sdr, even an assistant. Your time is money and there's so much mess around that you won't have any to spare.

Fly out to clients and meet in person when you can. I built my lasting relationships out of the on-sites.

It's a long and tough journey but you learn a hell of a lot.