Is my Skilsaw 3410 okay to learn on?

It can be a perfectly reasonable saw for learning basic ripping and crosscutting, as long as the fence locks securely and the blade is aligned. I wouldn’t expect it to have the refinement of a higher-end saw, but you don’t need that to get started.

Since the bevel lock is broken and the height wheel isn’t secured, hold off on using it until both controls work properly. Check that the blade guard and riving knife are present and usable too. I’d avoid putting much money into repairs if the costs start approaching what a sound used saw would cost.

For the missing hardware, bring the crank wheel and any leftover screw or pin to a well-stocked hardware store, or ask a repair shop to identify the size. A parts diagram or the manufacturer’s service information may help confirm what belongs there. Don’t force a screw that only seems close. The wheel needs to stay firmly attached, and the bevel lock needs to hold its setting without slipping.

Once repaired, check the saw’s alignment and make a few cautious test cuts before trusting it with a project. If the fence, blade, or adjustment mechanisms still feel unreliable, keep the saw unplugged until those issues are sorted out.

Short version: yes, if it’s sound and you can get those controls fixed safely. A table saw is more versatile than a miter saw for many general woodworking cuts, but it’s awkward for breaking down large sheets. If sheet goods are most of your work, a circular saw with a straight guide can be a practical first step instead.