With those parts suggest you look at using something like the free App Inventor, or one of the many other such platforms.
https://appinventor.mit.edu/explore/
If you search Ytube you will find many Mobile/bluetooth/Arduino examples.
I would suggest you first look at setting up the Arduino to do PWM LEDs, you can use a simple 5mm led driven by the Arduino to do that ,adding you driver and high powered leds later.
Your sensors can again be set up separately and gives you chance to ajdust them as you need.
Again you can find all these as popular projects on the main Arduino forum and many other such websites and Ytube.
When you have everything working directly from the Arduino, then is the time to look at your bluetooth control.
If you are new to Arduino then start off with one of the many tutorials,eg
For what you want to do the humble Arduino Uno will probably be fine and you can pick up decent clones on ebay etc for £5.
Better to blow up a cheap clone while you are experimenting rather than an expensive Mega board.