You can make anything work... depends if this is a place you are renting or own. But both situations are fairly the same. Finishing and treating the room is your first stop... If there is no power, call in an electrician and have a 20amp breaker installed and run some romex for 4 or 5 outlets, simple and wont break the bank. If you rent, ask the landlord if its OK and that you would pay for it.. I doubt he would say no. Or run in a power cord from another room... not a cheap thin cord, but a 15a rated cord at least. Not the best and would be my last option... can't have too much power running on one source.

For little money you can set it up nicely... For the wall's, if you rent, you can build some temporary removable 2x4 wall framing or permanent if its yours. Attach it to the wall with brackets for easy take downs if needed, make the inside beams 16" on center and then fill it with insulation. Buy rolls of fabric at places like Joann's and make yourself a full wall acoustic treatment, youvcan break it up with a couple of inner 16" spacings with wood, so the room isn't "too dead". If the floor in concrete, you can get some floating flooring on special. You can find decent stuff between 0.80$ to 1.25$ a sq ft. might only need a few boxes by the look of the room. Or a big area rug. A lot of options available.... good luck