The answer to your question depends on two types of info that only you can provide: Your individual preferences and your assessment of the odds.
Let's assume a 0-10 utility scale with 10 as the highest preference. Your status quo has a certain utility to you with 100% certainty (since it's already in place), let's call this S. Becoming a realtor has different possible outcomes, each with different utilities. Let's assume a best case outcome, called R, where you become a realtor, enjoy it, and have a long fruitful career. Let F be the outcome where you try and fail... you've spent time and money on classes, maybe even got the required credentials, but can't make it as a realtor and have to spend a few years getting back to your current status quo level.
How would you rate these different outcomes? There's no absolute "right" answer, this is very subjective and specific to your preferences.
For example, let's say you decide:
S=5
R=8
F=1
Now, what is your best estimate for the odds of being successful in your area? Doesn't have to be perfect, but is it 50/50, 20/80, 90/10... this is not a place where you want to let your ego get the best of you. It's one thing to deceive others, another thing altogether to deceive yourself. Be realistic.
Let's say you determine, to the best of your ability (e.g. after looking at market conditions, talking to other realtors, how many realtors there are relative to homes on the market, your personality fit for the job, etc.), that odds of success are about 40%. If so, then the expected payout is 8*.4+1*(1-.4)=3.8, which would be less than what you rate the status quo so don't do it. You can plug in different numbers to get different outcomes. With the values of S, R and F above, the probabilities of success would need to be about 57% or greater before it's worth taking the risk.
The real value of this exercise is to get you to stop, break things down into component parts, ponder your own relative preferences, and to do the due diligence in evaluating the odds. Maybe your island is underserved and everyone is frustrated with the lack of good options for hard working realtors, which would make the odds of success very high (90% or more?). Or, maybe the market for realtors on your island is saturated and super competitive, which would make the odds much too low.