Can use of adapters harm the camera in anyway ??

The adapter should not be any harder to mount, or sloppy/loose etc...

Mount the lens to the adapter when you first get it, then see if the lens removes easily,

then mount the adapter to the camera without the lens and remove it, if there are no issues, don't worry about it.

One thing about adapters, if you plan to swap lenses(of the same type) very often the cheap adapters can become loose, there are ways to fix that(wedging a small flat blade screwdriver), or avoid it all together, and that is to get an adapter for each lens, or to get better "Pro" adapters that use springs vs. split metal.

FWIW, Ive been happy with my many Fotodiox adapters.

Go get a blower now! don't wait, and while you're there pick up some Eclipse lens cleaner & Pec pads(for cleaning the sensor & optics, or a micro fiber cloth for the optics when in the field), use the blower regularly, the more the better, it's simple prevention to getting dust on the sensor, blow the sensor, the mount, & the body cap, also blow the lens mount, and it's good practice to blow/brush the optics before cleaning them with the cleaning fluid & Pec pad, just a drop or two on the pad is all thats needed, be sure your hands are free of oils, as that will leave a residue on the lens.

What I do to clean the sensor if blowing at every possible angle does not remove some dust(An LED flashlight highlights the dust)...

I roll up a Pec pad starting at the corner, add a drop of Eclipse fluid to the tip, and paint the dust away.

Tip: The more you use the blower the less you need to do the rest. (I only spend a minute to blow the camera & lenses I've used, then they are ready for my next outing)