Automatic cell number generated by text in a different cell

Hopefully someone can help with a frustrating formula I am trying to create

I want to create a formula so if you enter text in a cell it enters 1 in an adjacent cell

Then the following line would enter the following sequential number

To make if even more confusing, I don't want the number shown in the cell until the text has been entered.

Therefore avoiding #value in every field.

For example

Job 123 Food123 1 £240
Job 354 Food256 2 £123
Job 112 Drink112 3 £112

??? - When you type a Job number in the following line 4 would appear under the 3

Many Thanks

Matt