Corrections in red.

Suggestions in blue.

Seoul Jazz Festival 2013

Today, my friend said to told (what you had was also correct, but using a verb like 'tell' is a bit more common) me that the "Seoul Jazz Festival" will be held in May; the line-up is fantastic! Kings of cConvenience, Wouter Hamel and Damien Rice.... moreover, it will be updated soon! Yay!!! I really expect look forward to this festival XD

Really well done! Just small errors. Also, you used a semicolon better than many native English speakers do. ;)

Seoul Jazz Festival 2013

Today, my friend said to me that the "Seoul Jazz Festival" will be held in May. The line-up is fantastic! Kings of Convenience, Wouter Hamel and Damien Rice.... moreover, it will be updated soon! Yay!!! I really look forward to this festival XD.

[Good work.  If you expect something, you simply are saying it is probably that it will happen, not whether you are happy about it or not.  I thnk you meant to say that you are looking forward to it - that you are excited and please that it will happen.]

Seoul Jazz Festival 2013

Today, my friend said to me that the "Seoul Jazz Festival" will be held in May; the line-up is fantastic! Kings of convenience, Wouter Hamel and Damien Rice.... moreover it will be updated soon! Yay!!! I really expect this festival XD (Yay!!! I really am excited for this festival XD)

정말 잘 하셨어요!