Welcome to the forum!
First, given the hardware you have; I don't see anything that looks incorrect with your traveler. You may experiment with leaving it longer or shorter, but given the hardware you have that would be the way to set it up. Your mainsheet is also rigged as it should be.
The outhaul is supposed to go through both of the holes on the end of the boom (and back once more through the clew, all for getting a bit more purchase). After the outhaul comes out of the second hole at the end of the boom there should be a cleat somewhere along the boom to tie it off. If there's none, you could simply start by tying the outhaul to itself. A bit crude and doesn't allow for adjustments under way, but gets you on the water.
Anyway, I'd start by just looping clew-lower hole-clew-upper-hole then tighten and tie the outhaul to itself. Then go sailing!
Now, most DS users eventually upgrade part of the rigging to suit their sailing styles. As you don't have a baseline, why not first sail the boat the way it is, but to give you some ideas of possible upgrades:
You have the two blocks for sheet/traveler connected back to back, so they can run freely along a fixed traveler. In my setup, I have only a single block and it is tied (with a knot) to the center of the traveler. However, instead of a line across as in your case, mine is a triangle that runs over two stand-up blocks on the transom (where you have the eye straps) and can be fixed (or released) as needed. If released, it works like yours, allowing the sheet block to travel downwind, but if fixed, it forces the sheet block to remain upwind a bit more, which can help with upwind trim. (It has a loop that goes over a hook under my transom; if unhooked it can go side-to-side, if hooked, it forms a fixed triangle).
(click to enlarge)For your first objective, that is, to get out and enjoy sailing, these are differences that don't matter.
For the mainsheet, I would eventually replace the block at the center of the boom with a ratchet block (Ronstan 55 is what I use and it works like a charm on the auto setting). I sailed many years without, so it can be done, but it was definitely a good upgrade. This photo shows the block, but as used for the jib sheet.
(click to enlarge)Similarly, for the outhaul, you want to eventually be able to adjust that easily while on the water. Here's a picture of my setup from a few years back, using small (18-20 mm) blocks.
(click to enlarge)However, I've moved on a bit from that. I've removed the single block lashed to the sail and just feed the outhaul through the clew as original; I've kept the double block lashed to the boom as the friction in the holes felt a bit much. The reason I removed the single blocks is that my new sails were so long in the foot that the blocks would be touching before there was enough tension; even though I already used the smallest blocks.
I'm using a V cleat on the side of the boom, about half-way to the center. Different from the photo, I now lead the tail forward and held parallel to the boom with a bit of soft bungee tied to the forward end (there's an eyestrap at the front of the book for that). That way, I can reach the outhaul from about anywhere and adjust it underway.
While your outhaul isn't easily adjustable, just set it for the highest winds you are likely to encounter that day and it should be fine for going out and getting some practice. (In strong and very! light winds, the outhaul should be tight to flatten the sail, in moderately weak winds, if it's a bit loose you'll get a bit more power). Given the choice, you might flatten your sail a bit more, as being caught in stronger winds with a belly in the sail may be more of an issue than sailing too slow in lighter winds (and, in lighter winds, if they persist, you may be able to reach the end of your boom for an adjustment, something not so advisable if you are overpowered...).
)
. Thanks again for making me feel welcome to the forum and the DSA.