Marie wrote:
I'm a teacher and I'm trying to use exel to do grades. How do I find the
total for a row of grades

That depends on the form of grades. If they are numeric points, the
answer is simple. If the grades are in the cell range A2:J2, then
enter:

=sum(A2:J2)

If you have letter grades, you will need to convert each letter grade
to whatever point system you might have; and perhaps you will have to
convert the sum or the average back to a letter grade, if that is your
intent. Since that is much more involved, before overwhelming you with
potentially irrelevant information, please indicate your interest in
this solution.

and then find the average against total points possible?

Do you mean "find the average of the row of grades", or do you perhaps
mean "find the percentage of the total possible points"?

If you mean the former, enter:

=average(A2:J2)

If you mean the latter, as I suspect, if the total possible points is
in A1, then enter:

=sum(A2:J2) / A1

You might want to format that as Percentage with 1 or 2 decimal places.
To do so, click on Format Cells Number and select Percentage.

HTH