Will it be correct if I say so "there is a long way from home to university"? Is it correct to use the construction "there is" or should I use "it is" instead? If so, why?
Both are correct but mean different things
There is a long way from home to the university
means that there is more than one way to go, and one takes longer than the others. So you might say
There is a long way from home to the university, but it is worth it due to the scenery.
It is a long way from home to the university
means that any way between the two is long.
"There is" tends to relate to existence.
"It is" tends to relate to universality.
I do not mean those to be universal rules, but they reflect common usages.