Very solid advice above.
I would add that unless you are used to exercising in the heat, take care. Lots to drink with electrolytes, suntan cream (baring in mind that sweating removes it) and stay away from the heat of the day. Mornings are best, but at a pinch the evening will do as well (although the heat will be rising from the sun drenched tarmac.
Also, without putting a dampener on your one day to cycle, getting anywhere memorable from and back to Can Picafort before the heat sets in will curtail your time in the "memorable" area. If it were me, I would take my kit, helmet and pedals in a backpack and take a local regular IB bus through to and back from Port Pollenca (where there is a good choice of bike hire and collect your pre-ordered bike that you have organised an early collection time) so I could do the newly resurfaced Cap Formentor route without wasting any time on the less memorable areas.
Truth is, you have to come back for a proper cycling holiday! A weekend would work - stay in Port Soller, close to the airport, to the sea and to the mountains!
Good luck, enjoy.