just push it back into the bumper bracket.... worse case is ear on bumper is ripped off, and or clips on bracket is broken.

if really no idea how to do, go nearest workshop/bodyshop ask for help, expect pay yam cha or more money

scratches, since below bumper & not visible from eye level, just ignore unless willing to spend $ on respray. some polishing compound may recude the obvious sign.

if DIY, free. knowledge also free.