You are talking about changing the tempo of a track. This can be done with many tools (probably all tools you would call a daw) including Reaper.
There are basically two approaches.
Compressing the wave. Imagine a given file of audio data is 44100 samples long and this took 1 second to play. If you kept all 44100 samples but changed timing so that that all played over a half a second, you would be compressing the wave. This approach will alter the pitch. Another way to think of it is turning up the speed of a turn table. Faster means higher pitch. Old jazzers and some guitar players would play a record at half speed in order to slow down fast passages and play along. This resulted in the same sound pitched almost an octave below the original. Fine to jam and practice with and at a reasonable pace for a student.
Interpolating a new wave. The idea here is to change the tempo without altering pitch. It is not immediately obvious how to do this computationally and involves some linear algebra. If your a programmer and are interested, I am reading a book by Craig Lindley that includes some easy computational algorithms in java that are open source and I could send to you.
Pragmatically, you should do this with Reaper or whatever other tool you are using. (Ableton, Audacity, etc.). They will almost certainly support method 2. But beware of the difference, and realize that you might be able to get away with altering the tempo of a drum track via method 1, as percussion is less prone to clash other parts of the mix because of some arbitrary shift in pitch. Imagine a vocal track on the other hand, whose harmonic relevance to the rest of the piece could be destroyed by a x.17% change in frequency.