First, the purpose of this session is to be able to make a pair of pants with no fear.
If this is the first time you have done pockets, you will love them and put them in everything,--I do. I love to have pockets to just stick my hands in when I am standing around.
Measure your waist. Measure your length from waist to where you want your pants to end. Measure your hips. (the widest part of your width about 8-9 inches below your waist.) These measures will help you pick a pattern size, and also help you adjust a pattern if you need.
If you have a pair of pants that you like the fit, you can take a string and hold it from your waist in the front to the center seam where it meets at your crotch-front measure curve. Then do the same in the back to the seam where it meets. This will make it easier to determine the fit of the pants. When you lay that string on the curve of your pattern piece, you can then tell if it needs adjusting.
These pants will have an elastic waist. You will need a piece of elastic, non roll if you have a problem with your waistbands folding over in your elastic waist pants. Non Roll elastic is the elastic that has a vertical ribbing going up and down on the elastic, so it is a little stiffer that just plain spandex elastic. You can use either for these pants, whatever your preference. Your waist length piece of elastic. You are going to be sewing a circle that is the width of your waist but a little smaller so it will hold your pants up. In sewing we use a lot of LOGIC. Just think things through-Why do we do what we are doing. We are going to sew the circle of the elastic so that is done and we don't have to thread it through the pants waist. We are just going to fold the waistband top of the pants over the circle you have made with the elastic-then we will topstitch it over the elastic band. It makes your pants quicker to make.