I tried to take cuttings from pelargonium flowers but someone told me that I should have left more leaves on the stalk. Will I still be able to propagate them like this
Pelargonium cuttings are very easy, so don't worry too much about doing things "exactly right".
Ideally you want to cut 3 or 4 inches of stalk, making the cut just below a leaf joint, and remove all the leaves except the top two or three.
You need some leaves because the plant can't survive without photosynthesis, but if there are too many leaves the cuttings will lose too much water and die before they have started to grow roots.
Most of the ones in your picture look fine, except for those which seem to have no leaves at all!
If all those grow, you are going to have a seriously large display of pelargoniums next year :)
You can always take more cuttings from those cuttings in spring, if you need more plants.