Why the sense strand is only involved in transcription though the antisense strand just has the compliment strand of the sense strand?
One of the reasons why DNA is double stranded--this means DNA has sense and antisense strands--is to make a copy.
During transcription, RNAs are transcribed referring to anti-sense strand sequences--making base pairs with anti-sense strand. In other words, the sense strand does not do anything during transcription.
Either strand of DNA can be sense or antisense. SWBarnes2 posts that the "transcription machinery will only bind on the correct orientation" and that is indeed what determines which strand is sense. But note his important statement "the sequence is not correct on the anti-sense strand FOR A GIVEN GENE" (my emphasis). As you move from gene to gene, the sense strand can swap strands. Coding sequences can overlap running in opposite directions, making both strands sense; this is more commonly a viral trick. Sense and antisense are defined by what sequence is found in RNA and so the map of sense and antisense strands on DNA is complicated. As you move along a strand of DNA one strand might be sense, then the other, then both, then neither.