If you want sound rather playful (as in, telling a friend) you could say 面白い話を聞かせてあげよう！ It sounds a bit posh, but that is how I'd say it (or even 面白い話聞かせてあげようじゃないか). If you want to be neutral, simply say 面白い話をします。

私は面白い話を説明しようと思っています ! good luck!

君に面白い話をしてあげる！ kimi ni omoshiroi hanashi wo shiteageru! :)

I think this is how you say it, but I could be wrong. 面白い話を話します.