Uso de messing up (mess up)

Hi everyone, how's everything? My name's Adailton Abreu and I have a question. So, let's go! How to use the idiom 'mess up' and 'messing up'? See, when I was watching 'Everybody Hates Chris' in 'Everybody Hates Greg', the Chris ask to Tonya why she didn't ask for somebody for help before she start messing things up. I found that messing up is equal to mess up. I wanna know what and when to put between messs/messing and up. I want more a thing, please correct this text that I wrote before. Thanks!