First board I ever designed, in KiCad. It's a two layer board with a ground plane on the bottom because I thought it suffices and will be the cheapest to manufacture.

This board will interface with CAN in cars through the OBDII port, fed by the 12V battery that is provided through a connection in the OBDII connector. Couple remarks: the large footprints are so because I haven't soldered many SMD components yet and I'm not that comfortable with it, so I'd like it to be as easy as possible. I went with the Traco TSR 1-2450e as DC-DC convertor because I've used it in the past and it's affordable, but I'm very open to alternatives, even if it's a custom power part on the board itself.

The MCU is an ESP32-C3 dev board (Seeed studio) for a couple reasons. Firstly, this is a prototype so I don't want to actually design my own circuitry around an ESP32-C3 chip (I don't even have the experience to do such a thing). Also, I want to assemble these boards myself, which would not be possible with a custom implementation without some expensive hardware. Having it assembles by the PCB manufacturer would be too costly.

This part passes DRC in KiCad with a few warnings about "Silkscreen clipped by solder mask", which I'm ignoring for now.

I've kept the signal traces at default KiCad width (0.2mm) but adjusted the power traces to be 0.8mm wide, which should be enough for both the MCP2551 and the ESP32-C3.

The ultimate goal of this board is to provide an as cheap as possible OBDII interface board while making use of an ESP32 (with BLE) chip (due to some code requirements).

Again, I am an absolute beginner. I really want to learn, so every comment is welcome. I might be very far away from a manufacturable board, but that's really something I'd like to achieve here. I read some beginner tips for PCB design (trace width, 45 degree routing etc.) and tried to incorporate everything.

Thanks in advance.

First ever PCB review