I think you are unlikely to end up with a sweet wine so long as you use a yeast that has high alcohol tolerance and leave it to ferment out. Commercial wine yeasts like ec-1118 (used in most wine kits) can tolerate up to 18%, so long as you stick to recipe quantities/ratios of additional sugar to fruit then it shouldn't be too sweet. The main thing to worry about is keeping stuff sterile and temperature, you want to be keeping to between 18-22 degrees in my experience so do most of my brewing in spring and autumn.
Starting gravity should be above 1.070, alcohol content will increase if you go higher than that by adding more sugar but I would stick to a recipe. Personally, I don't fret about specific gravity to the point that I chucked my hydrometer! I make a lot of beer and wine at home and find that if the brew stays at the right temperature, you stick to recipes, cleanliness rules and leave it long enough then the alcohol content will be close enough to what the recipe says. I think most modern recipes will aim for 12%ish.
One other thing, if you don't have a bottling wand then consider buying one or you might end up with most of your wine on you and the floor or full of air. Neither is a great. I flippin hate bottling!