How to start/advice for IOT project

Hi

I'm web developer since many years. My two hobbies are web development and triathlon (it require lot of time). And i want to associate them !

My idea is to start some iot project (for example create an bluetooth cadence sensor for "personal project", to learn some new things).

I must admit that i'm new to iot development. Have you some advice about it.

I will need to use some sensor (accelerometer ...), have you some idea where can i find it ? Have you some info about which material can i use to manager this sensors ?

I just want to manage programming part ? I was thinking of rust to discover it. Can i manage this kind of system with rust ?

Thank's