Dumb question! Need a formal dress!

MamaBear🐻🌼 • 26, Mom of two-proud Navy Wife & SAHM

Ok I don't know anything about dresses I know it's risky to order one online but I'm about to take my chances because I can't find anything in the stores... any suggestions anyone do this?

So most all dresses are to long on me, do I just take it somewhere to get it altered?

...what's your favorite dress website I wouldn't mind a deal... or any tips?