Blender Cycles Render Resolution Problem

Hi. I am relatively new to Blender and Blender Cycles render. I am having a lot of resolution problems in Blender Cycles Render. I have a scene set up in Blender and every time I try rendering an image of it, it comes out really grainy and I am not sure how to fix it to make it high-res. Please help if you can. I’ll post some images of the scenes but I am relatively new and I hope i’m posting this in the right spot. I hope I get some feedback on this. Thank You.

What have you set the number of render samples to be ?

I have it set to 100. Is that all I have to raise? Or will I just have to -trial and error- fix other presets? Thank you very much for your help. I’ll try to raise it and see if that ups the resolution.

Thank you so much for your help. Ill be sure to look at those links and post the finished images once I am done rendering.