There is a limit on weight/seat loading for a very good reason derived by factory tests and various calculations.
Aside from the W+B calculation, you have to ask yourself why you would exceeded an aircraft limitation!?
If you are honestly too big, and you still want to fly, loose the weight.
The most important thing to have why starting out as an aviator (not a pilot!) is to have the correct attitude.
Don't pay lip service at this stage and you will probably be on the right track
Ralph