I think we have easter because It is to celebrate the day that jesus rose from the death, just three days after his execution.
Why do we celebrate easter with eggs?? or bunnies! It’s because of jesus’s death on the cross. Rumour has it that on the 29th of March the earth was a egg and it had been hatched. I don’t think that is all true, but it makes you wondering.
The easter egg can mean that there's new life. Remember that jesus was born in a barn with all the chickens laying eggs. That could be the reason!