The diode across the relay can be any 1N4000-series diode (1N4001, 1N4002...).
12.5K? is probably acceptable, but consider a lower value, 4.7K?.
It looks like you are using the relay to switch ground to another device ('Disportivo' ?).
Sometimes it does not make a difference, but I prefer to switch +V and always leave the "Grounds" connected.
The associated diode there would prevent a reverse polarity. It is only essential if you reckon that situation is likely.