Pixelated render output, what am I doing wrong? Dear blender community,

So I'm pretty new to blender and general 3d creation and now I rendered my first good project but It has many point where the pixels doesn't belong to or the color of them isn't matching. I can provide a picture for that too. Would be greate if someone could help me. I can provide any additional information if needed. You can see the pixels mostly on the table and at the plant. I could remove some of them when I added another light that directly lights in the room but I don't really want that to be there because the picture is too bright then.
Thanks for helping!
From what I see and understand from your description, you are seeing something pretty common when using the Cycles renderer: Noise. (The bright pixels are sometimes referred to as "fireflies")

There are several ways of reducing this effect:
1) Try a higher sample count in the "render" setting 

2) Use one of the denoise options, for example this one: 

3) Switch to Eevee Render Engine: