If you are going to do Starting Strength, then do that.
If you are going to do SL 5X5, then do that (you need to download the spreadsheet from another site, it’s free.)
When you follow the program as is, you will see the progress. It even tells you about your question (if you bought the book).
Don’t change anything for now, just follow the program as is.
Don’t be afraid to eat. Just watch the mirror and adjust accordingly.