welcome to the forum! I always start with a raw (uncooked) shrimp. If it looks pink it's cooked.
I agree for the most part. The live rock you put in will have some die off and that will be enough. Typically most cycles take about 4 weeks some longer some less. You will see brown "dust" covering rocks and sand, that is the diatoms dying off because the nutrients are depleted ie end of cycle. This is when you need the test kit. Make sure your parameters are in the green. If nitrates are high do a water change give it a week and test again. Now that the system is cycled you can start adding animals. Do it slow as your system is new and to much to fast will have a bad effect and could cause another cycle. Start a list of what you want now and know size and temperment of your fish that way you have an idea who to add first and last. Remember with that small of a tank the 1 inch to 3g rule is a good to go by rule almost 1 inch to 5 gallons would be better. Your tank is small and filtration on stock biocubes is adaquate at best look into a nano skimmer and chemical filtration like purigen. IMO both things will help you be sucessful in keeping of salt water animals in a small tank. Once the tank is cycled start doing regular water changes of 10% weekly to help remove nitrates and get on a schedule this will also help you be sucessful. Hope this helps welcome to MR and welcome back to the hobby. Hope you are sucessful this time and are able to stick with it!If you want to save yourself a lot of hassle of testing and putting fishfood/dead shrimp in your tank, you could just wait about a month. Then after you see the diatom bloom recede you should be good to go. Otherwise you may think you had your spike and jump the gun, which happens quite often in this hobby.