How can I get rid of these white dots like particle? I tried increasing clamp value seeds and even the render but still not working.
I see so its with the samples. I wonder why I dont need to increase a lot of samples when I follow along with the Coffee cup tutorial in youtube, and it already looks really fine and smooth.
without a link to the tut no one can tell you 
, I can think of a few reasons it worked better in tut, theres even a few ways to remove the “fireflies” in your setup without increasing the samples so much (changing mats / lights) . Post your blend and you will get the best advice on your mats etc but without blend increasing samples is the easy(only) answer
I think that noise are the caustics. For a lot faster rendering you can check “no caustics”, but then you won’t get as “realistic” result. Also adding more/bigger light sources to the scene might help some, but then ofc your lightning will change…
Setting the clamp to 1 should cure the one bright pixel, try rising the clamp value a bit if it darkens the image.