When i input data into a field i am trying to have it auto populate the same data into another field. How can i do that? Please help.. been stuck on this

Also, if the field is a drop-down, you'll want to set the calculation to get the drop-down value (instead of the drop-down designation.  Here's an example where I pull the Account Type from the Account into the Contact Record:

getDropdownValue("record_type_list",related($accounts,"account_record_type_c"))

Also, if the field is a drop-down, you'll want to set the calculation to get the drop-down value (instead of the drop-down designation.  Here's an example where I pull the Account Type from the Account into the Contact Record:

getDropdownValue("record_type_list",related($accounts,"account_record_type_c"))