There is no -the- way to approach your issue. It completely depends upon what you want achieve.
One approach is to resample your note in the 12 notes of the chromatic scale. Then you will be able to construct all the scales from the western 12 note system.
Resampling into the 12 chromatic notes will also allow you to use the hit and miss system of just use your ears as I have no clue what I am doing as suggested above.
Another option can be to resample the notes only into the scale you like. Typically this will be 7 or 5 notes for western music. This will make sure that it is easier not to hit any wrong sounding notes. But depending on the complexity of your chords and chord progressions some notes (especially in the 7 note scales) can still sound off unlike what Phillip suggested above.
Sampling only a scale can be very handy if you play pads, as you wont need to dedicate 12 pads to one sound.
Furthermore, if you are into arabic or atonal music, you might need to sample 24 notes or more as those systems are not constrained to just 12 notes.
If you are interested to continue making music I suggest that you try to learn at least some theory. As suggested above you can just use your ears, but with some theory understood you will be able to know what selection of notes over specific chord progressions will give you which feeling. Furthermore, it will be a lot easier to remember and repeat what have been playing as you can fit it into the system you have learned.
Typically, the hit and miss method will be fun in the beginning, but you will usually hit a limit on progressing pretty soon (as you might be experiencing this very moment)
So yeah, musical freedom and just doing freely is a very nice thing, but usually works far better if you have learned the traditional way first.
On top, we have not yet touched the topic of needing multiple scales when the song is transposing.
So yeah, you did indeed open a can of worms, very nice worms Id like to add as you are getting to know each of the worms in the can more intimately.
Have fun, try out a lot, and the more you know and the more you practice the more it will become second nature to play around with these things. And once you step in, dont give up, and embrace that you have just started a lifetime of learning and enjoyment once you start to learn with the right focus and energy.
And lastly, be brave and dont do stupid 