First, congrats on the internship! Feel free to contact me - my email is in my profile. Happy to help by making some intros or giving you some pointers.
A few things that are important in almost any BD or sales role:
1.) Know your product inside and out. It's hard to sell something when you don't know what it is or what it does.
2.) Ask a ton of questions. Ask your prospects what their needs are, ask current clients what they like and dislike about your competitors, ask other BD/salespeople in your org to bcc you on their emails so you understand how they're selling, etc.
3.) Read and research a lot. Read books about entrepreneurs or companies you admire, read advice from other salespeople on Quora, research your competition, visit your prospects' websites to glean info about them before a call, etc.
4.) Understand how your product or service can be genuinely helpful to each customer and get good at being able to concisely explain this to the customer.
5.) Be patient. You will have days where it feels like everyone says "no," days where the product team pushes a release back and screws up a big sale, days when no one can make up their mind on your product, etc. Be patient and keep moving forward.
