Based on the LED's forward voltage of about 1.7 V (from D1) and using a 3.7 V supply, you can compute the necessary series resistor value assuming a typical LED current of 20 mA. Using the formula:

This gives a resistor value of 100 Ω. This is a standard value from the E12 series and should work well for the LED at 3.7 V.

A good next step would be to add a resistor (for example, a generic resistor such as Generic Resistor) with a resistance of 100 Ω in series with D1.

For a typical voltage divider using an LDR (like R1), a fixed resistor of around 10 kΩ is usually a good starting point. This value helps set a moderate midpoint voltage for detecting changes in light levels. Depending on your specific application and the LDR's characteristics, you might need to fine-tune this value later.

You may add a resistor, such as Generic Resistor, with a value of 10 kΩ in your circuit.