You came to the right group. The fact that enthusiastic canoe paddlers generally don’t care for aluminum boats doesn’t mean much. For learning the basics, you can’t go wrong with the old instructional films by Bill Mason. Based on your comments about paddling alone, check out the first link, and if you will paddle with a partner, check out the second.
https://www.nfb.ca/film/path_of_the_paddle_solo_basic/
https://www.nfb.ca/film/path_of_the_paddle_doubles_basic/
Chances are this kind of paddling is more involved than you currently think you will need or be doing, but the more genuine technique you can learn (rather than just grabbing at the water with your paddle and switching sides every couple of strokes like most people do), the less frustrating it will be. One thing that Bill Mason doesn’t mention is how important it is to keep your blade close alongside the boat, with the paddle shaft being vertical as seen from the front or rear. That keeps the blade closer to the centerline so less correction is needed to counteract the boat’s tendency to veer away from your paddling side. Most people reach out at an angle with the paddle, which accentuates the boat’s tendency to veer away from the side you are paddling on. Keeping the paddle shaft vertical is described by some people as “stacking your hands”, which helps to visualize the technique, since the hand that’s on the top grip of the paddle will be directly above the hand which grips the lower part of the shaft. What you will see most amateur paddlers do is position the top hand well inside the boat. That’s comfortable, at least when learning, but wrong.
Bill Mason describes a few different forward strokes, but you’d best start out learning the J-stroke. Learn to do a good J-stroke and you will be in good shape on the water.
To get into the boat an unimproved landings, position the boat parallel to the shore (again, this is opposite of what most beginners do, but that’s why most beginners have so much trouble with launchings and landings). Keep it lightly beached or tied up while loading/unloading your gear, then push it out a bit so it’s floating before climbing in. When you get in, step onto the centerline of the boat, and then get the rest of your body over that same location while bringing in your other foot. Easy rules to remember are to keep your body over the middle of the boat when getting in and out, keep your head inside the rails at all times, and keep your head straight above your own middle when moving above within the boat. Following those rules will generally keep you in good control. Oh, and don’t use the gunwales as handrails until you have mastered the feeling of using both of them equally. With your hands on the gunwales, as soon as you put more weight on one hand, than the other, over you go.
A center seat is definitely a good idea for solo paddling. The next best thing is to paddle facing backward from the bow seat, though that’s not possible with a lot of aluminum canoes as there will often be a thwart in the way. The bow seat is farther from the front of the boat than the rear seat is from the back, so the boat is less out-of-trim when you sit backward in the bow seat. When sitting there, put some ballast way up front. It could just be a bucket of water (that way you have a lot less weight to carry to and from home).
A lot of solo paddlers who don’t want to be troubled with the complexity of canoe paddles opt for using a double-blade paddle (like what kayakers use, but usually longer). You might want to have that as an option no matter what, when starting out. For choosing a length of double-blade paddle, 230 cm is about as short as most canoers go, but many use paddles that are way too long. Don’t make the paddle it any longer than you need for reaching the water fairly close alongside the boat.
That might be more starting info than you need, and if so, maybe it’ll be food for thought, at least.