i was pretty weak myself when i enlisted. that time i can't even
do proper push ups. i broke 0 after field camp. only 2, 3 towards
the end of BMT. did 7 finally on the 2nd last day of BMT. now can
do more than 12.
so trust me, u can do it, no matter how weak u are. all u need is
practice. u can do push ups right? start by doing push ups when
ever u have the time, during tv advertisments etc. make sure u do
stretching before and after push ups, to relax those muscles.
your technic is very important too. that i'll leave u to find out
yourself, cos different people their technic is different. for the
time being just aim for breaking 0, once u are able to do 1, it'll
be very easy form then on.