Poem for Calligraphy Art
There are four basic types of calligraphy: 
   1.Regular Script(楷书)
   2.Semi-cursive Scrip(行书)
   3.Clerical Script(隶书)
   4.Cursive Script(草书)

Normally I'll recommend start with Yan Zhenqing - Duobaota Bei. But I think Ouyang Xun - Thousand Character Text is better for you to try. It's covering lots of basic knowledge and widely used as a primer for teaching Chinese characters to children. Below is the link.

https://zh.wikipedia.org/wiki/%E6%AC%A7%E9%98%B3%E8%AF%A2#/media/File:%E6%AC%A7%E9%98%B3%E8%AF%A2%E8%A1%8C%E4%B9%A6%E3%80%8A%E5%8D%83%E5%AD%97%E6%96%87%E3%80%8B.jpg

So far I never see any Chinese calligraphy poem (ancient classic) is about love.