How much will I earn in my first month blogging?

This question will be very hard to answer only because there are a lot of things to consider. Setting out for the first time blogging will create a lot of challenges for you, I would recommend that you get familiar with how things work and give your self sometime to absorb your surroundings.

Don't focus on the money right away because you might get disappointed if you don't start generating revenue within the first month or second. If you are an experienced blogger, and have been working with services like AdSense, Chitika, then you might have a quick results, and may see your earnings quickly but if your just starting for the first time then there's so much to learn, and will require some time to explore what it takes to generate revenue

I think this subject is on most bloggers minds when they start out and sometimes it will discourage you from reaching your goals, so hang in there and make it work. When I first started out blogging I had no intention on making money with my blog. But after blogging for sometime now, I learn enough to help me to start earning money with my blogs, and you will also start earning. 
Here is a the Google AdSense guild that will help you get started Google AdSense Guild