Page 1 is for the sleeveless blouse, 2 and 3 are for the skirt. The pattern pieces include an allowance of about 1cm.
The bell skirt is very high-waisted and flares slightly from the hip. The blouse will fit M or L bust. A larger bust piece could accommodate DDy.
The bust piece should be gathered at top with elastic, and the sides gathered a bit so that when attached the front and back blouse pieces are the same length.
Use the 1 cm square as a guide when enlarging and printing the pattern.