Christineka -- one of the tricky parts about working with Russian recipes (if you're American) is that they quite often measure things like flour and sugar by weight (in grams) whereas we measure those by volume (in cups). But here's a good website that not only gives you weight-for-weight and volume-for-volume metric conversions, but also has a weight/volume conversion table for a bunch of common dry ingredients like flour, sugar, rice, etc. So for example, 100g of sugar will be about 1/2 cup.

For measuring the pumpkin (which I assume is given by weight in the Russian recipe), you can either use a kitchen/postal scale, as a Russian cook would, or you can figure that 250 g of cooked, pureed pumpkin (i.e., as in canned pie filling) would weight just slightly over a half-pound.

I really don't know about the packet sizes for vanilla or cinnamon, which would presumably vary by brand.

P.S. If you're still not sure about the measurements for a given recipe, or you want someone to double-check your translation of the recipe before you actually start cooking, you can post a link to the recipe here, and I'm happy to give you a second opinion -- I'm a reasonably experienced cook.