Beginner: Fade out/in transition

I have seen "Basic Introduction to Kdenlive" from nixiepixel und some things are different. Also I am a little bit familiar with elder Vegas versions, which influences my thoughts probably.

I want to make a simple transition, which fades the 1st clip out and the next in.

I mark a clip and then there are 2 possibilities: the green arrow in the right upper corner and the right mouse button. With the green arrow I can't get a transition selection window, which "popped up" in the video.

When I use the right mouse button, I can choose between 5 transitions. Aren't there any more?

I chose a transition and play the clips. In which monitor should I see the transitions? I can't see a transition in any monitor. Could it be because the cpu is too slow? I use a ff1-codec with the avi-clips.

Is it possible to make a simple transition by drawing a clip over another?

How can I mark all clips from a clip to the end?