What to do with my small room?

Hi you guys; first of all I have to thank all of you for such a useful forum. I'm a newbie to designing home studios; my main purpose is to record vocals, to have a place to do vocal trainings, and to have a quiet room to play my instruments (digital piano and electric guitar) and here's the situation:I've got a 3.2 m* 2.6 m( 126inch * 102 inch) room and I'm planning to construct a home studio. So here's my first question: is the size of the room appropriate? I'm asking this because I don't know what to do with this space. should I divide the room into a more closed room, like a dead room or should I use isolation and acoustic treatments on the whole room? my second question is what materials I should use. I myself was thinking about using Stone wool to isolate the walls, but I don't know what kind of stone wool (with different densities) should I choose. some people told me to use stone wool with density over 120, but what I learned in this forum is that if the stone wool density is between 50-80, the isolation layer happens to function better. I'm using carpet as the floor padding, so should I isolate the floor with any specific material? how about the ceiling? I thank all of you in advance. BTW: I'm from Iran and I not familiar with your metric system! so I used meters and inches.

Greetings, welcome to the forum. You might want to read this post. As for your space, it's pretty small, could make a usable control room or edit suit. But I don't think you have enough room to be able to divide it up into another space like a vocal booth or live room, etc...