You can actually test your bars out as early as you want, just as long as they don't zap...... although as I sometimes say- you can even test them out even if they do
zap just to get the idea of what a lye-heavy soap fees like, but just be aware that the experience definitely won't be as pleasant as when they don't zap. lol
Since you are very new to the craft, my advice would be to take a fresh, new, zap-less bar aside and test it out (wash with it) about once a week all throughout the cure period in order to see and feel the changes going on in the soap (take notes!). Then you will have a better idea of when your particular soap formula is 'ready', or the best it can be in terms of bubbliness, longevity, mildness, etc....
I did the same thing when I was new and found out that my own formulas are at their earliest best
at 4 weeks, but they get even better after 6 - 8 weeks have gone by.
Keep in mind that what one considers to be their "earliest best" might be different from what another considers to be their
"earliest best", but on average, 4 weeks seems to be fairly normal for an 'earliest best'.