A huchi is a young woman who has many casual sexual partners or who dresses or behaves in a sexually provocative way.
There can be slight differeces (as a consequence of different dialects): "Alles Guete zum Muetertag" - That means "All the best for your Mother's Day" There's no "happy..." in it. The "all the best..." formulations are also used to say "happy birthday", etc. in Swiss German (and German).
Usually, kids wear things like graphic t-shirts and some really cute jeans that have a design on them! They also like to wear those sneakers that come in all those different colors with the white strings, but you can decorate or buy more colorful strings. On cold days, you could wear a sweater with a fancy design on it...