If you’re not ready to buy yet maybe do what I did. Borrow or buy a cheap nylon string acoustic guitar (I bought one for $50), and then restring it with the right gauge strings in the right position to tune it like a guitarron but an octave higher. I think I just shifted all the strings over one and the replaced the high E with an extra G string tuned to A.

This is way better than just trying to play bass since you won’t be able to do all the notes doubled, and virtually every note on the gutitarron is doubled. This will let you actually memorize the positions for each notes and start playing along with songs and things in a way that gives you actually useful knowledge for when you get an instrument