how do i delete everything in my downloads folder

Just like you'd delete anything in your mac....

You can actually quickly do it in the Finder, with three key presses:

1) Command-Option-L to open the Downloads folder (or click Downloads in a window Sidebar, or open it from your home folder)

2) Command-A to Select All

3) Command-Delete to move the selected files to the trash (or drag them to the trash if you prefer)

4) If you are sure, empty the trash (Finder->Empty Trash)

In Finder >> Go and refer to image below

Then Drag and Drop to Trash and Empty the Trash

ohhh, I want to ask the same.