Rookie mistake, I am sorry to say Nothingness. Your individual tracks should be at an average of -18dBF* or even lower, if tracking a live show for example you could record at -30dBFS to allow for peaks. This all assumes that you are recording at 24 bits which gives you s DIGITAL dynamic range of over 140dB, i.e. vastly greater than any analogue system in the chain, even the very best 'pro' AIs only achieve rec/play DRs in the low 120dBs.
Sample RATE can be 44.1kHz in almost all cases but a case can be made for 96kHz if very high levels of high frequencies are being tracked. Not often a problem for the beginner.
So, signals bumbling around neg 20 and peaks no higher than about -8dBFS. IF the odd signal does blast past 0dB there is 'clip recovery 'software, I bet Reaper has some but...last resort.
*Decibels Full Scale. This is the meter sacle of your DAW and is THE meter you should use when tracking. Obviously take notice of any 'clip' LEDs on the interface (RTFM!) but your DAW is telling you most of what you need to know.
Dave.