To get pieces into good positions common sense it's enough. Just play strategically simple openings, develop your pieces, aim at the enemy king. The italian game and the bishop opening are two possibilities. Against the sicilian i suggest the open(1.e4 c5 2.Nf3 (every decent move) 3.d4) It gives you an attacking position, for now you can simply follow a standard plan of quick queenside development,0-0-0 and pawnstorm on the enemy king. The need for some theory will come later.
You can't play a single sistem AND constrict your opponent. It stands to logic: different responses, different counters. To play sistems like the london with good prospects you have to study MORE than if you played a "normal" line.
But the most important thing is: at 1700 level, no more than 1 game out of 20 is decided in the opening.Below, i think 1 out of 100. For now just plat chess while thinking to basic principles:
-Development
-Development!
-Central control
-Castle soon
-Make threats, play actively
-try to understand the reason behind the opponent's move
Studying theory is a very little thing that will not help you until you have reached a certain level. In my case for example i can say that by trading all my opening knowledge for 1/10 of tactical strenght, i would instantly gain 100 elo points.
I'm looking for some sound opening systems that should get most of my pieces into good positions and constrict the opponent as much as possibly. The chess I play is at school standard so I can't expect the opposing player to make any corresponding moves or come back with anything to edgy. As a beginner, all advice is welcome :)