Step one... Well, I'm going to throw a caveat in here. Lots of people would say don't touch anything over a couple of years old. Fear, illness, death, cooties (This is a big one, I don't think you can get rid of them!), and plenty of other reasons. You are going to have to use your head along the way and really asses what you are using.
I, however, am a firm believer that age may reduce flavour and nutrient value, but if properly sealed you should not have an issue with death or illness. As long as you are not dealing with massively rusted cans and pin holes, you should be fine. If a seal has let go there will be pretty obvious signs. Mold, lack of colour or muddy colour, lower liquid levels, off smells, bad odor, and poor flavour. This is also the order in which I would assess things to make my judgement, sight, smell, and then taste.
I think you are on the right track. Wine is the best use for this, except maybe a few jars for the pantry if they are from the last few years.
You are going to have to do a little fiddling and get creative. You can try different balances of ingredients, but the end goal is the same as Bigdave mentioned above. You will just need to replace the recipe fruit component with juice and preserves.
You can start with juice, add preserves to increase specific gravity and add additional sugar/water to adjust potential ABV. Smashing or blending fruit solids might help to release sugars giving you a more accurate potential ABV reading. Mesh bags make racking and clean up much easier.
It might also be a thought to make a recipe with frozen berries or fruit so you can get an idea of how a must tastes. I find they range from light and sweet to aggressively sweet and jam like. Tasting another recipe or two might just offer a guideline to gauge fruit and juice content.
1 gallon batches are great for experimenting.
You don't want to ferment in your carboys. Use a bucket with extra head space to accommodate stirring and foaming.
Depending on the recipe and the ingredients you choose, you can add things like raisins to improve mouth feel. Lemon, orange or other juice for acidity and flavour. Rind to really impart more citrus and lemon flavour. If it's a dark berry or 'thick' juice you can get more creative with chocolate powder, pepper corns and other accents in smaller amounts.
The way I see it, you have nothing to lose. Water, yeast, and sugar are cheap and other than the ingredients in the list you have above, it's about all you will need.
Wine is forgiving and a recipe is not law. They will give you a good guideline for required nutrition, acid and tannin levels, but you can adjust fruit and sugar as you see fit. Your hydrometer will ultimately be your sugar/water gauge.
Wash (Scrub) and sanitize your equipment. You might want to consider a wine/beer sanitizer for after your first cleaning with soap and bleach. Bleach compounds can react with cork and taint wine. Some won't even wipe a counter in their prep area with it. It is forbidden!
Other than that.. Just time. Many youtube videos imply you can have wine in weeks. It is ready when it's ready. Meaning it tastes good. If it is mediocre, time can make it better, so can tweaks. If you don't really like it, you can still make it better months later before bottling.
