One true statement about the Senate is there are 100 elected senators. Another true statement about the Senate is, in order to be a senator a person must be over 30 years old, a citizen for 9 years, and reside in the state the are running to be senator of.
The guidelines for the Senate are set forth in the U.S. Constitution. The Dirksen Center website has a list of statements and explanations about the U.S. Senate. The center's mission is to educate citizens on the functions, roles and guidelines of the U.S. Congress in order to increase citizen engagement with government.