makeup on for the rest of your face I don't wear makeup (just eyeliner) so I don't know much about makeup but I realize i have horrible red bags and i feel concealer helps but I have a glow under my eyes so I don't know if that is tacky to just have that and then not have any other makeup on the face

It would look bad if you don't wear any other makeup the concealer would look like a half a circle.

No. Just make sure you you a color that matches your skin tone and blend it in.

if you don't wear other make up to blend it, concealer may not be the best choice. try an under eye "bightener". also, applying a highlighter to the corner of the eye and along the sides of the top of your nose (proximal to the eye's corner), will steer the focus upward away from your bags.