put the target at whatever height you can...i put them at a turkeys height usually...just always did. with a new gun id start at 20-25. starting with light loads wont hurt...but like it was said unless you have adjustable sights or a scope it really isnt gunna matter because your turkey loads will shoot way diffrent usually. i goto "turkey shoots" and they shoot light light loads there at 20yds or so. closest BB to the dot wins the prize for that round. my turkey loads will rip that target in half at 20yds. light light loads just dont pattern well..im sure they are reloads and only have a little bit of shot..im convinced of that..but i guess it wouldnt hurt to try a few and see how they shoot if you got some laying around. then i would move back from 20 to 30. then 35, 40, 45 etc till you no longer get a killing pattern. you can get free printed turkey targets but i dont care for them. i like life sized ones and staple them to a pallet i use as my target frame. when patterning a new gun or load or choke ill staple news paper over the whole pallet just to see if the bulk of the shot missed the turkey or what..pain in the butt...but i do it just to see whats going on. if the gun is really brand new i might even run a box of light loads through it...clean it..then pattern turkey loads. i just like to shoot my guns and get familiar with them though. id also try to get a buddy or a couple buddys to go in and buy a bunch of diffrent turkey loads then you all split them up so you all get to try DIFFRENT loads. very seldom do you get a good patterning gun from the first load and choke combo you try. exspecially factory chokes. my gun came with a factory turkey choke and it just didnt compare to an after market choke tube. best money i ever spent was on heavy shot and a after market tube. if getting with buddys isnt an option try what you have..then maybe here and there pick up a 5 or 10 shell box and try them out..turkey loads can be pretty pricey..i like to stockpile them after the season when its all on sale then pattern the next year and see what i like...till i went to heavy shot atleast..good luck...