A crowd is a large group of people. Generally a crowd is a group of people with no particular order, jostling together.
You can also use crowd as a verb, as in "to crowd in together" which means putting a lot of things in a small space.
You feel proud when you have a good feeling about something that you have done, or something that someone else has done. A parent may be proud of their child who has just graduated university. A child may be proud of making a very good painting.
The boy in the picture is proud of his newborn baby brother.