Awesome French

Heya, to say 'to keep up' as in to keep up with the trends, the times etc. Could I say, 'il peut etre difficle se mettre au diapason' to mean 'It can be difficult to keep up'

Forget about the diapason thing, “to keep up” is an idiom, you have many verbs to replace it along with the context. 

Keep up with the trends : suivre la mode, être à la mode
Keep up with the times : vivre avec son temps
Keep up (alone) : rester informé, suivre