Hello,
I've been more than four years with learning classes with an IM, but the economic problems force me to dismiss them. With him, I created a very appropriate opening repertoire, easily maintained and adapted to my style.
My play style is well suited to open, tactical game, where there may or may not attack to the king. I am a player who operates well in position with initiative and dynamism. With white I play E4 looking for a game with isolated queen pawn positions. Game against d4 I play tactic lines of Slav defense.
My problem stems from the need to change my black repertoire against e4. Currently is based on the modern Philidor (1.e4 d6 2.d4 Nf6 3.Nc3 e5 4.Nf3 Nbd7 ... etc). It has worked regularly because it does not fit very well with my style. With my teacher we were looking at the possibility of changing it to something more suitable and not too complicated maintenance. As classes were disrupted, we could not find an opening like this.
Could someone give me some advice on what to use against e4 opening that meets these characteristics and does not require a very large study?
Thank you.

I am rather confident that at our level nothing requires "very large study". I suggest an e5-based repertoire. 

1.e4 e5 2.f4 d5 exd5 exf4 leads to a very open game which might suit your tastes.

1.e4 e5 2.d4 exd4 c3; i don't know, i'm happy with the schlechter defence ...dxc3 4.Bc4 cxb2 5.Bxb2 d5 6.Bxd5 Nf6 7.Bxf7 Kxf7 8.Qxd8 Bb4+ but it might be too dry for your tastes.

1.e4 e5 2.Bc4 Nf6 3.d3 c6 intending a quick d5 is a nice aggressive option.

1.e4 e5 2.Nf3 Nc6 Bc4 Nf6 is worth some study but is both strong and entertaining.

1.e4 e5 2.Nf3 Nc6 3.Bb5 Nf6 4.O-O Bc5 is a defence i'm recently taking up myself, it leads surprisingly often to bloody fights where black tryes to hold the balance by somply developing at full speen while white is distrupting his pawn structure. There is some good analysis of this line avaiable online for free.

1.e4 e5 2.Nf3 Nc6 d4 is a line i struggle against so i don't feel like suggesting anything. Maybe someone else can complete this repertoire.