喜欢 is a verb. the same as "like"; for instance: 我喜欢你!I like you!
欢喜 is a adj./adv./n. equal to the words "happy; joyful; gladness" such as: 1. 满心欢喜 be full of gladness in someone's heart. {It's a noun in this phrase at this time} 2.我喜欢看着你满心欢喜的样子。I like to look at your happy face.{I don't know how to express grammatically, could you tell me in English? Thank you.}{by the way "的",generally, stand for adj. for example, 快乐的,高兴的,难过的;他快乐的跑着,跳着,唱着找不着调的歌。 难过的时候,男人喜欢唱歌。 } 3. 她充满欢喜地拉着小提琴。 She play the violin with great joy.{"joy" is a noun in this English sentence at this time but it is a adv. in Chinese.}