The spreadsheet "introduction examples" has three sheets to look at.
Complete the lists on the "lists" sheet and do the tasks on "formatting" and "formula and functions" sheets.
Your teacher might go through this with the whole class.
You might also be given it as a MS Teams assignment; if not you can download it and open it from this link
In this introduction there is a series of four basic spreadsheets with tasks to do on each one.
You might be given them as Teams assignment(s) - if not you can download them from here
Download and open: The basics 1 This spreadsheet gets you to practice adding by using:
=CELL_REFERENCE + CELL_REFERENCE
Download and open: The basics 2 This spreadsheet has two sheets.
1) "this one first" gets you to practice using the + - * / operators in formulae.
2) "then this one" gets you to write formulae using more than two cell references.
Download and open: The basics 3 This spreadsheet has two sheets do the "simple" sheet. It has more practice at formula and then introduces you to the autosum button and the SUM formula. Do the "advanced" sheet if you are ahead of most people.
Download and open: The basics 4 This spreadsheet has two sheets do the "simple" sheet. It has more practice at the SUM formula and then you try the AVERAGE formula. Try the "advanced" sheet as well.
Well done you have completed the Introduction to Spreadsheets.
Make a new spreadsheet, enter some numbers into it and try some of the other functions out.
To find them click the fx button or More Functions from the AutoSum drop down menu.