MY SELECTION TOOL BECOME A ROLLING EDITION TOOL WHEN I PUT UPON THE FINAL OF THE CLIPS

Check your settings in the Preferences / Trim > Allow selection tool.....

Mod: please do not write in capital letters (considered shouting) and for some users difficult to read.

This is what happens when you hover over the in our out edit point of a clip. Your clip is too small for the cursor to hover over the center, but zooming in and out (+ or - on the keyboard) will help you out here.