The things you have asked of in your question are all rituals and mustahabb acts related to a newborn child. Since birth is a very blessed occasion, Islam has certain rituals for it, namely:
1- Shaving the baby’s head: It is mustahabb to shave the baby’s head on the seventh day after its birth and give its weight’s worth of gold or silver in charity. Weighing the hair can be done using the precise scales used in jewelry stores that are used for weighing gold and silver. You can ask how much money that much gold equals. Of course, all of this is mustahabb and doesn’t mean you have to do it and if you choose not to, it doesn’t mean you have sinned.
2- Aqiqah: Sacrificing a sheep and giving its meat in charity for the health of the newborn.
3- Circumcision of newborn boy: It is better to be done on the seventh day and not be delayed after that. After coming of age and religious puberty, it becomes wajib upon the individual himself if it hasn’t been done yet. 
4- Walimah: A banquet in which at least ten people participate in.  It is mustahabb for a meal to be given to the relatives and neighbors when a baby is born and it is better to use the meat of the aqiqah if they have had one done for the baby. 
For information on the reason for circumcision, see: The benefit of the foreskin, Question 6433 (website: 6495).
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