How do I delete a track that is clearly wrong?
Tap on the item to go into the details view, then go into EDIT, then “Edit individual segments”.
From there, you can tap on each segment, then choose SPLIT / Split segment, to extract out any useful data, while marking the clearly nonsense stuff as “bogus”.
As a rule of thumb, try to mark any data that’s within 100 metres of the real location as “stationary” (or as the correct moving type, if you were moving at the time). But any data that is more than about 100 metres from the correct location at that time, mark it as “bogus”.
That way you can preserve any sensible / usable data, separating it from the useless data.