The age of consent is the age at which the law says a person can agree to sexual activity. If you are 16 years old and above, you can legally have sex (or do another sexual activity) with another person who is 16 years or older as long as you both agree to it.
Can a 16 and 30 year old date?
This means that its against the law for someone to have sex with someone under the age of 16. It wouldnt be illegal for someone whos 16 to have a relationship with someone who is 30 - unless that person is their teacher or in a position of authority.
Can a 29 year old date a 16 year old?
In most states in the U.S., Yes, the 16 year old is considered a minor. However there are some places (and some U.S States) 16 is the age of consent, so although a 29 year old and a 16 year old may not have much in common - it would certainly be legal for them to see each other.