select first blank cell in row -insert value and loop to next row

[daz457]

I have a table of data approx 25 columns and roughly 100 rows.
Each row has data but also blank cells(see image)
What I would like to be able to do is run a code that looks at each row in turn.
It would find the first empty cell in that row
Insert "1" into this cell , disregard any other cells on this row and then go to the row below and do the same.
Loop until it does not find any more rows to look at.

I have trawled lots of code, I can find the first empty cell in a given row and then manually insert a value, but cannot loop down to the next row, very new to VBA, I usually record macros and tweak as required, recording and adding bits of code as I go.

I am sure this is not too difficult but a bit beyond me

Thanks in advance

 

[daz457]

I rolled out the finished spreadsheet to my colleague today, we export a report from a SAP database and have been manually sorting, deleting rows columns etc. Usually a hundred or so rows which all need the first empty cells highlighting and a "1" adding to it. This has made a big difference to what was a bit of a tiresome chore.
Once again thank you both for your input and advice.