I can understand your state of desperation being a young man and without a job in hand. But then, you will need to keep many things in mind while trying for a job in Qatar.
First of all, there are many people across the world who are in a similar state as you are. They are equally desperate to better their lives and look forward to working outside their home country where the grass looks greener. So, there is some competition in the market. Remember, you are competing in a global job market.
Secondly, Qatar is a very small country geographically. While it has a very stable economy and growth rate, It does not provide that many job opportunities.
Thirdly, and you may not be aware of this, the government follows a quota system while issuing job visas. As such even if a job is available, there just may not be a work-visa available for your country.
Fourthly, your country Ghana is some distance away from Qatar. Cost of travel does count with employers and they keep this in mind. They therefore look for manpower from countries close to Qatar such as Nepal, Sri Lanka, Bangladesh, India, Pakistan etc. This becomes all the more true with workers in the lower categories such as laborers, carpenters, drivers, janitors etc.
Lastly, I am by no means trying to discourage you. You must keep on trying since sending an application through email costs nothing. But you must be careful though. There are people in Qatar ready to con you or people like you who are in desperate need of a job. There is something in Qatar called "Free Visa". There are some people who sell this visa. The business is illegal. Also, there are many times such visas are simply bogus. So just watch your step, and keep your head high.