I need to print my excel sheet but the print is too small that is barely readable
How can I adjust to a readable size
You might need to set "Print Area" if that was not done earlier. You can do this by selecting Page Layout >> Print Area >> Set print area.
You can also adjust the width, height and scale under Page Layout >> Scale to Fit.
If any of these didn't solve the problem, you might a sample of the file after removing sensitive information so we can assess together.