Hi there. I have added an insert (amp simulator) to my audio track which I am recording guitar through a m-audio 2x2m c- series. I have had no trouble recording but can’t same to figure out how to change my guitar tone. Even after selecting different amp types and messing with the setting this doesn’t affect my input tone at all. this goes for all effects i have tried with my audio tracks. I feel like im missing something obvious but from youtube clips I have seen, as soon as they attach or create a new effects track this changes their guitar tone instantly. Please help thanks!!! 
Do not use “direct monitoring” but monitor through Cubase. See your interface´s and Cubase´s manuals and plenty of threads on the forums