1.) If there aren’t enough (or any) buyer requests in your category, that just means there are not buyers currently looking for what you sell. Buyer requests also do not come out on a set schedule, so sometimes there are no new ones released that day. Your gig is also in a very, very narrow niche so it is going to be difficult to find buyers for that until you level up. You can learn more skills and put up gigs in more categories where there might be more buyers in need. You can also market your gigs off Fiverr. Fiverr is a LOT of work when you get started. Just making a small amount of money is not easy, although lots of books and websites say otherwise. Check out the Fiverr Academy for all kinds of info.
2.) If a buyer is interested in your offer, they will either contact you by message or place an order. Either way, you will see it come up on your Dashboard. If they message you with questions, you’ll have to discuss what the buyer wants to know, but don’t do any work until they actually place an order. You will know if an order is placed since that starts a clock counting down until delivery time.
3.) When you complete the job, there will be a green button that says “Deliver” on your order page. You can send attachments as a part of the delivery.
All of these questions and a lot more is in the Fiverr Academy and the Support Team knowledge base. I strongly recommend that you read both of those areas extensively and read the Tips for Sellers forum for information. Next time you have questions, please post the in Conversations or FAQ or Improve my Gig depending on the type of info you need. Tips for Sellers is a place to offer tips to others. You will gain a lot by reading before you run into trouble. Good luck.