Hello,
I want to know if it is hard to create an altcoin, introduce it to an exchange website, and advertise it.
Have you to spend money for that?
Yes you have to spend money to hire developers and hire graphic designers (for the logo etc...), unless you know all the required programming knowledge (from building the coin (C, C++), building the website (HTML, CSS,J, etc...) , building the wallet & phone app). So yeah , It may not be that hard but It's definitely not an easy task to do without money.