How to make a rotation animation in blender 2.8

I am completely new to 3d animation and blender 2.8 and after going through a bunch of tutorials especially blender guru, I managed to create a model which looks like a cpu fan with origin at its center and the fan is rotated 90 along x axis. Now the normals on the fan are all facing in different direction. I would like to rotate it continuosly along its origin so that it can be viewed from any angle but have not the slightest idea how to do so. A detailed tutorial would be much appreciated. Thanks in advance.

Is the fan is separate from (what i assume is) the (fan’s) casing ?

If yes, click “Object” in the Properties panel on the right
then right click the Rotation numbers once and click “Insert Keyframes”.

image

Now, move to a different frame on the timeline, change the rotation of the fan so that it rotates, then add another keyframe.