Birthday age calculation and fist name and last name under one field

Good day,

I am new in using this framework and I am not good in coding. So I came here hoping for you to help me.

My problem is I have created a Doctypes named “client_details” inside the doc type
the fileds are


I have 2goals for this

  1. To caluclaute the age after the input of birthday
  2. The first name and last name inputs should be combined in on the fullname

Please help me achieved this goal

Thank you so much

Below are some screenshots