Young or old, Bilbo has typical feet for his kind which means that he doesn't wear shoes and his feet have a slightly larger appearance than you would expect for someone so short in stature. This fantasy creature's feet are normally hairy just past the toes and up towards the ankles and you'd expect the hair color to match up with the hair on a Hobbit's head.
These feet can be purchased as accessories and I'm showing my favorites off on the left. You can also get some funny slippers which look like bare and exaggerated feet which would work well too.
If the costume event is an indoor one, you could simply have bare feet and use some skin safe glue to attach some furry fabric to the front of your feet.
For an outdoor event, you could think about some inexpensive white canvas shoes which could be painted using spray paint or acrylic paint to match your flesh tones and then you can easily glue some furry fabric on top which would give you your own DIY feet. One sure way to wreak your look is to wear a pair of normal shoes - that's not in character at all.
Find more info on making and buying on my Hobbit Feet Page