how to calorie count a beans and yam recipe

Hello, i am new to calorie counting, and i am trying to lose weight by counting calories and documenting what i eat on myfitnesspal

so the story goes, my house has a huge amount of bruces yams, which are gross, but it was either eat them, throw them away or give them to the food bank and i decided to eat them because i'm too lazy to take them to the food bank.

so i decided to eat them with food that i like, two cans of bushes baked beans maple & cured bacon. and it makes of big pot of yams and beans,, and i'm eating the contents of this pot 3 cups at a time

so the recipe is
1 can of bruces yams, 29oz = 823 grams with 850 calories
1 can of bushes best baked beans, maple & cured bacon, 28oz, 792 grams with 840 calories
1 can of bushes best baked beans, maple & cured bacon, 28oz, 792 grams with 840 calories

so the total weight of my recipe is 2407
the total calories is 2530
if i divide 2530 by 2407 i get the calorie per gram 1.05
and if one cup is 250 grams
i do 250grams a cup x 1.05 calorie per cup = 262.5
262.5 calories a cup x 3 cups = 787.5 calories per meal

my question is, is my math right? and how do i put this into myfitnesspal? how can i document this in myfitnesspal? do i need to make a recipe? how can i document this in my diary?

thank you