Microscopy; Relatively large spots on unknown...

Hey there to you too!

I suggest you don't have a problem at all. You are focusing on a ground glass filter somewhere in the light train. This serves the purpose of diffusing the light to give even illumination across the field of view.
When setting up, firstly use low power and a simple, easy specimen. Focus on this then rack up the condenser untill you see your annoying speckles. Rack up the condenser a little more untill the speckles just go out of focus. This is the position where your condenser should be for normal use.
Setting up the light source is the most important pre requasit for a good image, and there is a lot more to it than what I have already mentioned.
If I can be of any further help......Don't hesitate

Cheers and good hunting...Dave