Question
I want to move from point B to point A in the image, but Home and End jump to the beginning and end of the timeline and I can't return to A. In ↑ and ↓, you cannot return to A unless you press ↓ three times. If the clip is long, pressing it dozens of times will take time.

Answer
Move the playhead position on the arrow keys.
You can also move the playhead with Home or fu+↑. However, simply doing this will also affect clips on other tracks, so it may not work as desired.
There are several ways.
If I disable "automatic track selection (yellow circle)" for short track video and audio in edit mode, even though B has a playhead (red bar). You can go back with "↑" once. Once you set the corresponding track in edit mode, you can do the same in cut mode.

When it comes to the beginning of the selected clip (selected clip?), how about creating a marker ("M" key) in advance at the place you want to return (the beginning of the clip) and using "shift + ↑"? Markers can be dragged, so you don't have to create them each time, so I think it's convenient.
If it's Speed Editor, I think it's a little better if you press "SCRL", spin around to the approximate place, and adjust with "JOG".
Refer to the following site for shortcuts