Hi ...your "design" looks like the Shadow 200 UAV.

Be careful to properly calculate your tail volume. should be around 0.8 S.tail/S.wing*distance between N point Mac of wing and N point Mac of stab / wing Mac...

you should position your main undercarriage at a point which is 15 degrees behind your C of G . and your nose gear should be positioned at a point that it will carry 12% of your plane's weight.

the offset of your main wheels position will determine your "force" amount to lift your nose of the ground. The far the wheels are from your C G the more force it will need.

Your plane looks like it can easily fly on a 10Hp engine with ~5hp for cruise. what is your wing loading....??? At your application usually each horse power can lift 5~7 kg with a Rate of climb of ~800 ft/min. What airfoil did you use what CL-max and at what CL did you position your wing?Also how did you calculate your tail boom and your wing spar?

It looks like you are using a 3W-150cc....A prop of 28/16 will fly this bird very nicely.