I2C is a bus protocol that allows for multiple devices connected only using two pins.
The only requirement there is that each device is individually addressable - some sensors allow for different addresses for exactly that reason to have multiple of the same sort on one bus.
For porting libraries there are some threads to get you started
Porting from Arduino to Particle.io (Simplified-Hopefully)
[solved] Porting from Arduino to Particle
If you get stuck, just shout out 