Connecting lines, 90 degrees and on equal height

I have to sign pipelines for my education. However, I struggle with alignment. Because of the perspective, I don’t get connections properly. It is important that I keep my corners 90 degrees and that I connect my lines at the same height.
is there a way for that?
sorry for my English.

Use the cursor keys to lock inferencing.

thanks for your response but that’s not enough.
I’m looking for a way to connect a two points that must remain the same in height and only with 90 degree angles.
Connecting the two points does not have to be through 1 line, but is also allowed with several lines.
I don’t know how to clarify this properly.
but it concerns, for example, gas pipes in a house.

i have already made something but it was hard to allign the lines. I think and hope there will be an easier way.

Do you see the axis system (red, green, blue)?
Is the model you are working on aligned with this axis system?

If so, then it should be very easy for you to draw those angles at 90 degrees, and the inference and dimension systems to help you draw at the desired heights.