If you are a novice, you don't even want to consider building RF gear on that frequency.
Without lots of specialist test gear you would have no idea how well your transmitter was
working, if it had a clean output etc so that it didn't interfere with other people !!
PLEASE use premade modules and leave you novice activities to working out the interfacing
of the sensor to the transmitter and detection parts to the receiver module
Cheers
Dave