The book New Sales: Simplified by Mike Weinberg is a decent intro to sales that you would probably get a lot out of. You can only learn sales by doing but this book will help you get your feet wet - there are a lot of absolutely awful sales books out there but this one is good. 45 calls in 3 months is very easily achievable, by the way, even just doing cold calls from LinkedIn.
I'd like to add one thing. It's not a direct response to the questions you asked but I hope it can help you once you figure out how to start making calls. I used to sell engineering software to heavy industry customers. I found out very quickly that if you called a customer on the phone (or were on Google Meet or whatever) and asked "anything wrong? anything I can help with?" they would tell you "oh no, everything's great here!". Go visit them in person though, and ask for a tour of their plant, and all of the sudden they're pointing to all sorts of things saying "oh yeah, that new 10 million dollar unit they just put in won't start, we can't figure out why!" and guess what, the software we sold could help them figure out how to start it. I work remote now and I love it, but for sales? Nothing beats meeting in person.