M1 and M2 system requirements are different like php version and needed php extensions. You can use any virtualization technique like docker, vagrant. I suggest you can use docker, it is very light weight, we can create separate container for M1 and M2, in this way we can separate the system requirements without any conflict.
Alternately, you can achieve without any virtualization technique, directly create two vhost one for M1 and one for M2, you have to enable dual php which means php5.6 for M1 and php7.X for M2, you can do this by .htaccess.
