Can you tell me how to start my project?

Hi,

my name is Marlon and i am doing some research for my bachelor thesis.
I would like to work with bluetooth beacons but i don´t know wich one is the best for me.

My goal is to measure the distance between a smartphone and the beacon and see if there are some deviations.

Can you tell me wich beacon could me the right for me? And does it just work with an app? This seems very easy but i am not sure.

Thank you very much!

Marlon