I have a hundred legs but cannot stand.
I have a long neck but no head.
I cannot see;
I’m neat and tidy as can be.
Answer: Broom
The answer to this “What am I?” type riddle is “broom”. If you were google-ing the answer, you would have seen this is one of the more common riddles out there.
I have a hundred legs but cannot stand.
The hundreds of legs refer to the bristles on the bottom of the broom. Brooms, though they can stand when leaned against the wall, are not able to stand without support.
I have a long neck but no head.
The neck of a broom, aka the stalk, has no “head” portion to refer to.
I cannot see;
I’m neat and tidy as can be.
Brooms are used to sweep and keep things tidy, so the last two comments refer to the function of a typical broom used in house cleaning.