If different cams where used to create clips or if the cam was one time used horizontal and one time upright,- how can I bring these clips together in one video, showing all of them upright and not 90degrees fliped?
You need to apply the Transform effect to those clips and rotate them accordingly.
If there are many to be rotated, add them to one track and apply the Transform effect to the track. That rotates all of the clips in that track.