This is absolutely normal and he sounds like quite a happy little fellow. There are two explanations for the circling behaviour, esp circling your feet — one suggests a happy bunny who is in love with you. The other is that it indicates sexual behavior and the bunny is in love.
Rabbits - like any animal - have a range or variety of sounds. While they do not purr, one of the ways one can ascertain happiness is a soft grinding of his teeth. It is very hard to hear and you need to listen closely and carefully to him. However, just like extraordinarily loud purring can indicate a cat is ill or in pain, the same is true for rabbits and teeth grinding.
Rabbits do not really chirp so I do not know what that could be. They do "sniff" however and that may be what you are hearing. Has he had his first vet apointment yet? I am just wondering about dental issues - you may want to make sure all is OK is fine with his teeth. Since the noise is when he is circling, it is more of a mating call I suspect. I hope you will be having him neutered soon - bunnies, just like male cats liove much longer and healthier lives once neutered. They are not frustrated from needing a mate so they do not mark their territory all the time - and bunny urine used for marking has a nost distinct smell. You would much prefer your bunny to claim his territory and belongings by chinning them rather than marking.
Here is a good intro for new bunny owners: