You should be able to use the Blueprint node “Find Look at Rotation” which I believe will achieve the rotation that you want (it doesn’t affect roll). As for making your camera pitch upside down, I believe there are options to alter the rotation limits for each axis so that you can pitch past 90 degrees etc. Also this thread may help you:
You may need to do some separate handling with Find Look at Rotation so that it works properly with going upside down.