HELP!! whats the risk if someone knows my I.P. Address?

They could take over your computer by attacking from ports.

if someone knows your ip address, they know your isp, your country, city and even street address. hackers and thieves can infiltrate your system and steal personal information, they may cause damage to your computer, use ddos attack to you and flood your bandwidth. they can even spy on you. there are ways how to hide your ip address, using proxy or other software. you can also use firewall to secure your computers and to block any attacks coming from the internet.