Cutting:
Cut the pattern pieces out of your fabric. Place the selvages parallel to the center. The pattern pieces should all lie face up. Always align the thread arrow in the same direction on all pieces and parallel to the selvedge of the fabric. Transfer all the clips from the pattern through a 3mm long incision with scissors or chalk and mark the ends of the darts . Clip the seam allowance in the fabric fold because this is always a center. 
To sew this dress you will need a sewing machine and an overlock sewing machine, or alternatively the zigzag stitch on your sewing machine to neaten the cut edges.
Be sure to use a jersey needle and use a stretchy stitch, i.e. if you are sewing with a household sewing machine, you should use either a zigzag stitch or the three-part elastic stitch and then all seam allowances again with a zigzag stitch or another appropriate stitch Neaten so they don't fray. In addition to the description, the colorful lines in the pictures show you where a seam needs to be sewn or something needs to be glued.
When sewing, pay attention to the seam allowance included in the pattern.
Have fun sewing!

We continue with connecting the front and back parts. If you have a cut from size 42, you still have to close the bust dart on the right side of the front. Then place both pieces right sides together and close the side seam with the side cutout. Iron the seams apart again.
Now it's time to integrate the circle into the page. But to do this you first have to gather the hole
When you're done gathering, you can pin the circle. Of course, place the edges right sides together again. When pinning, pay particular attention to making sure that the clips are on top of each other and that you don't sew the circle in the wrong way around! Finally, neaten up the seam allowances and iron them outwards.
Now place the other side seams on top of each other and sew them together. Iron the seam apart.
We continue with the shoulder. Sew both shoulders together and finish them together. You then iron the seam allowance into the back piece.
Next, take care of the neck hole. To do this, iron the strip together in the middle.
Unfold the strip and sew the open ends together. Now you have a ring.
Now put the ring on the neck hole. You have to place the clips in the strip in the middle front and back. The seam of the sewn ring goes on the right shoulder seam.
You have to iron the sewn strip inwards and sew it close to the neckline.
Now you come to the sleeves. First, overcast the edges of the sleeve seams. Then fold the sleeve together and close it. Iron the seam allowance apart from this seam. Finally, you can fold in the sleeve hem twice and sew it in place. The sleeves are now almost ready to be sewn.
The next step is now clear: insert the sleeves. For orientation there is a shoulder and a front part clip. Finish the seam allowances together again and iron them into the sleeve.
And finally all you have to do is fold the hem in twice and sew it in place.