Congratulations! You'll get some emails from eBay and PayPal. If your Auto Ordering is setup correctly you'll also get some emails from Amazon or whatever the source market was about the order confirmation. If the order failed you should get an email from Easync about the order failing. Here is a link about order fails, the causes, and how to fix them, read that article if your orders failed and see if you can find your order fail reason and how to correct it, then come back here.
Again, if the order was successful you'll get a bunch of emails. You might get tired of these emails after a while so create some filters on these specific emails so you don't get bothered by them. You'll get an eBay sale email, a PayPal "You've got money" email, an order confirmation, then a few days later you'll get a shipment notification, and sometimes you'll get a delivery confirmation. I have all of mine filtered out except for the eBay sale notification and the Easync Fail Order notification. So on any sale I'll only get the eBay "Your item sold" email, and potentially the Easync Fail Order email; so 2 emails at most per order.
Your buyer will have the ability to leave you a feedback and rate you on your Detailed Seller Ratings. These are your 5 star ratings, you'll only see this after 10 feedbacks have been left for you.
You can be rated on 4 categories. Below is an example of mine at the time of writing this.
Item as described1917 (Buyers can always leave you feedback for this)
Communication1934 (Buyers can't rate you on this if you don't message each other)
Shipping time2006 (Buyers can't rate you on this if the item arrives on time)
Shipping & handling charges2076 (Buyers can't rate you on this if you have free shipping)
About 50% of the buyers on eBay leave feedback. If you get a negative feedback there are ways you can have it removed and their ratings for you will also be removed. Usually you can prevent them from leaving you feedback in the first place if they ask for a return/refund or open an item not received case against you. I have written an entire article on this here if you want to read about it now.
Read this next article here to learn about how to prevent losing any money on your sales.