Pulling Specific Data from copies of main template sheets

To put it in very plainly:

I have in my workbook 2 sheets:
Week 1
Data 1
The 'Data 1' sheet takes information from specific cells in 'Week 1.'

Now, within the same workbook, I'm making copies of both Week 1 and Data 1 (renaming to Week 2 and Data 2 to input new information regarding the second week) However, I do not know which formula to use, that it will automatically take information from the same specified cells but from the 'Week 2' sheet (NOT 'Week 1).

How do I do this, without having to go into every cell of "Data 2" sheet and manually re-entering i.e. ='Week 2'!a3 and so forth....

Thanks so much!

Thanks so much Ali...sometimes thinking way too much and not seeing the most obvious answer.