Data Cleanup - ignoring blanks, ignoring rows with string values etc.

Hi,

I have a list of data imported from another source, in several worksheets, which I want to combine in a single worksheet, with only the viable records displayed. I can do nothing about the source information (ERP system, with a BP which will charge me an arm and a leg for making changes to this report).

The source information have all sorts of blank rows, subtotals, page break indicators, repeat headers and what not that I do not need, and will be a disturbance in the new sheet.

This is where I am at:
i want to write a code that says,

if cells(rownr,1).value = "blank"
skip row

but i do not know how to reference the blank.

then, i want to run a check on column C(qty on hand)
if the value in this cell equals a string, or is blank, then row must also be skipped

Picture of data attached, data that must be skipped in yellow.

This should get rid of all the lines i don't need

Have tried general internet search as well as searching this forum, but not coming up with anything that will help me.

Thank you!

Oh, silly me, found the way to deal with blanks - ""

Still need to know how to check if the value is a string... Anyone? Please?