1) You can use the template search.php and searchform.php as your starting points. Creating a Search Page Codex
2) As far as the custom query goes, you can use pre_get_posts hook to test if you’re on a search page, then you get $_GET your values, edit your query accordingly. Action Reference – pre_get_posts
There are tons of tutorials online and questions on this exchange to help you out. Some are Simple and others are more Complex. You’ll have to do some real research to accomplish this. Hope it helps!