I am looking to create a microcontroller to record my heartbeat and movement data. This device would need to be powered by a battery.
I am a noobie with microcontollers but have extensive coding experience
What would people suggest is a good starting point?
Suggest Raspberry Pi Zero.
Small size, Linux OS, Bluetooth, Wifi, I2C port, SPI x 2 ports, Hardware PWM 2 channels, many GPIO pins, camera interface.
But can be a battery hog, 200mA when sending images from camera to web page.
About 100mA when idle.
And what would you suggest for the sensors? connect them straight to the Zero?
Connection depends on the sensor and voltage it requires.
Many sensor today are 3V logic which is compatible with the Pi Zero and they use I2C and SPI interfaces.
My suggestion of the Pi Zero is due to its small size and cost and the number of interfaces it has. To me it seems a good starting point but may not be the best solution. Really depends on what you want it to do.