coroplast airplane dimensions ratios

hi !
this is my first plane , made of coroplast(sunpack) , with 45 inch wingspan , i m not sure bout the horizontal n vertical stabilizer area , what are their ratios w.r.t wing area ,
weight of wing is around 800 grms , and wing area is carved out to be 400 inch square , 45 * 8.85 ,
also i m using a 3 arm 10*4.7 propeller , and 2200 mah battery , what could b possible reasons for not taking sufficient lift .
how to adjust center of gravity just before flying , i m balancing plane(slight nose heavy) , from 1/3rd of leading edge of wing using my thumb .
, any comment or trick will b of my great importance