For the first collection item you can use a simple calculation to retrieve the first index value.
=INDEX(Collection.Drop_down,1)
For the second one, you might want a more complex calculation. If the user can remove rows and there is a chance the collection might only have one item, you need to verify there is more than one row.
For example,
If you tried INDEX(Collection.Drop_down,2) but there is only one row in the collection, you will get an error message on the form.
So, you can use a COUNTIF function first to check if there are actually 2 rows, then put the index function inside of that.
=IF(COUNTIF(Collection.Drop_down,"<>")>1,INDEX(Collection.Drop_down,2),"")
This calculation checks if there is more than 1 blank field in the collection. If there is, it copies the value of the second item, if not, it leaves the field blank.
Just be sure to replace the "Collection.Drop_down" part with your actual variables from the > menu.