Power Raspberry pi and esp32-cam with battery

I am new to electronics. How would I power a Raspberry Pi, which requires 5V, and an ESP32-CAM, which requires 3.3V logic?

The two devices will not be connected and will be powered by separate battery systems.

I understand that I need a component between the battery and each device to provide a stable voltage. What type of voltage regulation should I use for each system (e.g. buck converter, LDO regulator)?

I am planning to source components from AliExpress.

I am planning to use a single-cell 3.7V Li-ion battery.