Close to good render, need help

I have been working on trying to get the right render, and I have an almost perfect render, but there is these ‘fireflies’ that I cannot get rid of in the glass and the glass just does not have enough shadow to it to fill in as much as I wanted. I have been rendering it in 4k because that has been what looks best, though I am not sure if that is the “best” for a final render, so sorry if this image gets distorted in the upload process(had to shrink to half size to upload).


I did follow this tutorialto help me get rid of fireflies, but the cup still has it bad.)