1. Recreate the Schematic in Flux
   • Manually place each component listed in your PDF (e.g., STM32F030CCT6, SGM2036S-3.6, ABS25-32.768KHZ-6-T, USB A Connector, keypad, IR receiver, etc.).
   • Assign correct values to passives (e.g., 1 µF, 4.7 µF, 100 Ω, 10 kΩ).
   • Wire all nets according to the PDF connectivity (power rails +3V3, +5 V, GND; MCU I/O; oscillator; USB D+/D–; I²C, SPI; keypad lines; debug header; buzzer, etc.).
2. Annotate and Validate
   • Label your nets exactly as in the PDF (e.g., +3V3_MCU, VBUS, SYS_SWDIO, IR_RECEIVER).
   • Run ERC to catch missing connections or decoupling caps—Flux performs real-time ERC in the inspector panel (knowledge-base guidance).
3. Assign Footprints
   • For each component, select an appropriate PCB footprint from Flux’s library (e.g., QFN for STM32F030CCT6, SC70 for SGM2036S, through-hole for the USB A connector).
4. Transition to PCB Editor
   • Switch to the PCB layout tab in Flux.
   • Import the netlist from your schematic to populate the board with component outlines and pads.
5. Place Components Strategically
   • Place decoupling capacitors close to the MCU’s VDD_ pins.
   • Group the oscillator and its caps near the 32 kHz and main crystal pins.
   • Keep high-speed USB differential pair traces (USB_P/USB_N) together, matching length.
   • Position connectors (USB, keypad header) at board edges.
6. Define Stack-Up & Ground Planes
   • Based on Flux knowledge: implement a solid ground plane on an internal layer to minimize ground-bounce and coupling (especially around switching and analog sections).
7. Route & Optimize
   • Route power nets with wider traces (e.g., 20 mil for 100 mA+).
   • Route signal nets with standard widths (6–8 mil).
   • Ensure matched lengths for differential pairs (USB) and critical clocks (SPI, I²C).
8. Run DRC & Finalize
   • Use Flux DRC to verify clearance, un-routed nets, and design-rule violations.
   • Address any errors flagged in the review tab.
9. 3D Check & Export
   • Use the 3D viewer to confirm component fit and clearances.
   • Export Gerbers and BOM when complete.

How do I start the PCB layout after completing the schematic?

Click the PCB tab. Your schematic components become footprints on the board. Define the board outline and arrange components based on the ratsnest. For more information checkout this Getting started tutorial