Is one month at the gym enough to put on some muscle ? how much ? and will protein help ?

Yes: You may gain up to five pounda, but more important is that you are building a habit and getting to be part of the gym culture. Creatine and an electronic muscle stimulator can be helpful if okay with your physician; a modest supplementation with cheap protein powder can help especially if you're not a big meat-eater. Make fitness a lifetime pursuit.