Video in the playback window in Premiere Elements 15 runs too slow and has no sound.

I'm not clear what you're saying. What do you mean by "No, it's not the case"?

Does a project with only video from your Canon have a render line over it and does it play smoothly?

No, its not this case, no orange render line above the video, I try to install new version of Premiere Elements (2018) and this is PrtScr of the failure, installation is not complete. I can open PE18, added videos not plaing, problem with exit PE18.

Those are two very different cameras, so it's going to be impossible for you to use project settings that match both cameras' video specs.

Try this. Start a new project. Load only video from the Canon camcorder into it. You should NOT see a yellow orange "render" line above the video as you add it -- and the video should play smoothly. Is that the case?

+GoPro 6

Eos 6D Mark II, I´m in Europe, Project settings: AVCHD 1080p, 50 fps, 1920*1080, other settings are grey (without settings)

What model of camcorder is your video coming from? Are you in the USA or some place else?

If you look under the Premiere Elements Edit menu, what is listed on the General page under Project Settings?

What operating system do you have? What processor does your computer have with how much RAM?

What model of camcorder is your video coming from and what is the video's format and resolution?

If you look under the Premiere Elements Edit menu, what is listed on the General page under Project Settings?