Judging by the music out these days and what is popular it shouldn't be that hard. Just do really easy rhymes that don't even need to make sense or mean anything. Then repeat one line about 7 times and add some oh oh oh's in there and you have a hit.
Think about things that interest you. Things that happen in society that are interesting. The thing with a song, is you need to write about things that other people can relate to. Did you have an interesting life? Write about it. SIng about it. That's what people want to hear.
As long as somebody else in the band can write songs I wouldn't worry about it. Not everybody takes an equal share in songwriting duty. Most bands have only one primary songwriter. For example, when Neil Peart joined RUSH he took on the duty of writing the songs because Geddy Lee and Alex Lifeson simply weren't at all interested in doing it.