How much sheet brass are you looking for? Shim stock can be purchased or you can find a local metal wholesaler that can sell you large rolls. If you want a large amount, I would find a chemical milling place and ask where they get their materials.
If you haven't soldered before, you should start off with a simple plug in iron. You need to get the hang of how it works before you start getting fancy, and they are cheap. Butane torches are nice, but can be tricky. I have a nice little Weller pyropen that has changeable tips, you can have an open flame, a solder tip or a hot air blower. All 3 come in very handy for various things. If you have a Harbor Freight tools nearby, they should have something similar. If you really want to be an expert, buy an expensive variable unit with a sucker and resistance terminals. It'll cost a few thousand, but can do anything.
As with anything, you'll have to practice to be good. Since you are in the Navy, can you try and get into a Mil Spec soldering course? Or even just the training materials? You might find it online. You'll also find a lot of tutorials by searching 'soldering'.
I think the best thing you can do is be specific in what you want to know. For instance, what on the African Queen are you soldering? Some railings? With specific questions, you will get detailed answers/suggestions.
A couple of important things to know, clean the metal, use liquid flux and good quality solder, don't cheap out on the materials. Isopropyl alcohol cleans up the carbon on the joint nicely and decent dispensers are helpful. You can buy materials at any electronics store. Also, joints that look nice don't always have strength. Have a few alligator clips of various sizes handy for heat sinks. Clean the solder iron tip before use and leave dirty when not in use(the carbon will keep the air from getting to it to oxidize it). Clean/wipe the hot tip on a damp sponge (not drenched) or damp paper towel before use(quickly) and never sand or file the tip, you'll damage the plating. If the plating gets pitted, the iron will still work, but won't give you good control, spend a few bucks on a new tip. If solder gets too hot it won't flow well. if it is hot too long it won't flow well. If you have the iron contacting the metal too long, waiting for it to heat up, your tip is too small and you won't get good flow. Have a selection of tips/irons for different size jobs. use fresh solder, not old solder that has been heated several times. Only put on what you will need. Having to file off solder may break the joint. Thin joints are weak.
For complex pieces, use a jig. Wood and nails/screws/pins work well, although it will burn and stink. plan your joining to try and keep the item from getting too hot and remelting previous joints. Not easy on 1/350 lattice masts!!
A short flow of work would be, measure/cut/clean parts. Set up in a jig. Heat iron to operating temp. Add flux to joint. Apply solder to iron tip so that it starts to bulge, but doesn't drip off. wipe tip quickly onto damp sponge, rotating to get the whole tip clean. add a little more solder to tip. apply iron tip to joint, wait for a second or two, flux will burn, solder should start to wick into joint. Apply a little more solder, if req'd, if joint is large, you can slide iron along it slowly adding more solder as req'd. remove iron and let cool. Check to see if joint is filled, apply iron again with a little more solder if it isnt. Remove tip from joint within a couple of seconds. put iron in back into metal holder, never place on table a table top to roll around. set up for next joint. That's how things should work, but don't always for various reasons. With practice, you should be able to come close most times.
These are just some of the things that pop into my head. There are plenty more and lots I don't know.
HTH's