Sure you can.. but it isn't legal (you would have become a cybersquatter) and you open yourself to legal liability.
Since you are new, you may want to use the search portion of the legal section and type"trademark" or "TM". Then spend about 3-4 days reading all the related threads to TMs (there are a ton). You can save yourself alot of worries and trouble. Just about every senario has been discussed, both pros and cons. This will help you a long long way.
sure.. if you want to become a cyber squatter and open yourself to legal liablities including real an punitive damages, plus loss of all monies earn, plus a fine of up to $100,000.00.
Since you are new, do yourself a favor and use the seearch box and type in "trademark" and tehn "tm" and spend a week reading all the threads (and there are a ton). Almost all senarios have been covered. This will save you time and money and headaches down the road.