Hi, your mental model is essentially correct, though it took me a good few evenings over a couple of weeks to get the workflow down in fusion 360. The electronics retailer will usually have the footprint and 3d model available on the component page. You can then import it, define which pins you want connected to each other in the footprint and in the PCB editor you can drag the routes (wires) to connect them.

Printing is way cheaper than I initially thought it would be - I paid £35 or so, including delivery and 5 of them arrived in 5 days. You can get cheaper delivery though. Also most of that cost is shipping and the setup fee - the marginal cost for each additional PCB print in the order is on the order of low single digit dollars.

Tbh my circuit was fairly simple so I just took a bit of a chance (and some extra care wiring things up). I think there’s a subreddit where people give feedback though I haven’t submitted anything.

For another data point: last week I ordered my first PCBs from JLCBCB. 2 fully assembled (parts already soldered) and 3 bare. $40 for the boards themselves, $40 for shipping, and $20 for US Tariffs, for total $100. Should take a week to arrive, shipping's cheaper if your willing to wait a month.

Re help: I asked for some help on libera ##electronics. I think there are larger communities on reddit that would also take a pass over designs.

My impression is that for straightforward circuits (not very high frequency or high power) you can get away with almost anything as far as layout goes. You punch in some generous setting for spacing of traces etc in the CAD software and it does some basic validation. (Are all the parts connected, not too close?).

I used KiCAD. It works well, though for assembly EasyEDA is probably lower friction. I had to dig around to find the right footprints for certain parts.

As a hobbyist, I have had a good experience using EasyEDA [0]. It's free to use, with the caveat that you are pretty locked in to their PCB ordering service from China. However, pricing is crazy good, like <$50 total for 5 PCB's (although there will be tariffs).

Regarding your mental model, it's more like a 2-step process. First, you draw the netlist, which is the electrical circuit diagram. It's this stage you ensure there are no short-circuits, etc. Then in the second stage, you drag-drop the components to the physical layout you want. The software then has an auto-router that references the netlist and automatically generates the first pass of PCB traces. You can tweak them if you wish. The EDA software also has a rules engine that checks for correct trace spacing, vias, etc.

For a "baby's first PCB", I bet you have more skills than you realize and I would encourage you to just give it a shot. Also, if you make a small mistake, you can manually "bodge" the board by cutting wrong traces with an exacto knife and/or soldering wires to the pads.

Everything else just comes from experience! If you're staying in the sub-kHz (audio) range, you probably won't need the crazy high-frequency tricks/trace capacitance/trace-length-matching concerns.

[0] https://easyeda.com/

Depends on complexity. The article gives a price, for 5 PCBs which isn't unreasonable. However this was a simple PCB that used a lot more physical space than it would need to (for this application most of the space was needed because of the physical space the buttons/sliders needed so it was needed so this isn't a criticism). If you want to make a small PCB much more work is needed. This was a few analog sliders and buttons - no high speed digital data, if you are designing a computer (even Apple II level complexity) it is a lot harder. If you are designing a radio there are a lot of complexity. If you want to get this FCC (whatever your local government is) certified there is a lot more complexity.

This project is something that should be easy for someone with basic CAD experience. However many projects require a lot more complexity, so don't think that because most people could figure this PCB out in a day make you think anyone can do more complex PCBs, things get complex fast.

If the board is small (10x10cm or less) it will be almost completely free, like single-digit dollars, through somewhere like JLPCB. So I’d say don’t worry too much about that, just jump in and try!

As for actually designing, it’s a little more complicated than that but not by much. I did my first pcbs with KiCAD ~5 years ago by pretty much just guessing and googling where things were. Completely feasible if you have 0 background experience.

jmb99 already said the part about cost/price. I just made a PCB for someone’s Halloween costume and it was only the 4th PCB I ever made. (So far I’ve used PCBWay for all 4 but since I’m in the US I also ended up doing a rush order from US-based Osh Park because I was panicking about how long the shipping was taking. Tariff situation has made shipping from China to the US more complicated. I found out DKRed, which is part of DigiKey, also makes PCBs in the US.)

For designing it I’d check out a kicad 9 tutorial playlist. You don’t need to know everything but it helps to know the right things, like how to run the design rules checker to make sure your PCB layout conforms to your schematic. There are a bunch to choose from but this one seems good: https://youtu.be/4YSZwcUSgJo

I haven’t done this but you can also try submitting your PCB design to /r/PrintedCircuitBoard subreddit for review, and they can also answer questions there.