No, you have to qualify at a marathon. Have you ever run one? If you haven't, why would you want to debut at Boston? The beauty of Boston is that you have to qualify at a previous marathon (and please do not choose Steamtown or another 'easy' marathon). Good luck.
QUALIFYING TIMES
AGE GROUP MEN WOMEN
18-34 3hrs 10min 3hrs 40min
35-39 3hrs 15min 3hrs 45min
40-44 3hrs 20min 3hrs 50min
45-49 3hrs 30min 4hrs 00min
50-54 3hrs 35min 4hrs 05min
55-59 3hrs 45min 4hrs 15min
60-64 4hrs 00min 4hrs 30min
65-69 4hrs 15min 4hrs 45min
70-74 4hrs 30min 5hrs 00min
75-79 4hrs 45min 5hrs 15min
80 and over 5hrs 00min 5hrs 30min
http://www.bostonmarathon.org/BostonMarathon/Qualifying.asp