Why cant the telescope see the target?

Recently, there are some small partners who have entered the astronomical pit, and ask how the telescope can't see the target.

Is the 1. cover all open?

2. do you install the eyepiece with the lowest times (the longest focal length)?

3. have you found your goal? (this is the most important part).

4. have you been careful? The above 4 problems have been solved, and they should not be observed through glass windows.

Note: finding a target is a prerequisite for telescope observation. Only when the target enters the telescope can it be observed. The target should be close to the distance, from big to small, and learn to use the star searching mirror to find the target quickly.