Go in with your eyes wide open.
It's a BRUTAL business. The barriers to entry are so low that it's impossible to make yourself stand out from other agents. When I lived in Plymouth, MA, and sold real estate there, there were 787 licensed agents in that one town. Something like 1.5% of the entire population of the town was licensed!
There's so much competition that you'll hear from buyers over and over "Sorry - I just found out that my mother's babysitter has a dog walker whose 2nd cousin's house painter has a 3rd cousin that's a Realtor. I have to buy from him to keep peace in the family". Even if you have a Buyer's Broker contract.
The buyers just don't care and your broker will be very unlikely to take them to court to enforce the contract for fear of wrecking their reputation.
And no matter how hard you work, buyers give you the same loyalty as they would a used piece of tissue paper.
Sure, you want to be a seller's agent. So does every single one of the other hundreds of Realtors in the same market. That's not a unique idea.
Having done residential and rehabber sales for years (and thankfully having gotten out of the business completely) my opinion, gleaned from experience, is that if you take a dozen agents who have been at it for at least 5 years full-time and have no other source of income, there's not a dime's worth of difference between them.
Part-timers are the absolute bane of the business, but that's another story.
Sure, every brokerage has a story about "we're better / we're different", but in reality, they just aren't - especially in a hot market. In fact in the red hot market of a couple of years ago, sellers really could FSBO and do quite well without an agent.
I'm very skeptical of the widely touted "studies" that say that selling through a Realtor gets you 16% more in the sale price. Every one of those studies I've seen were paid for by NAR or an affiliate, so they're not exactly objective.
Prepare to go for at least 3 months (probably much more) without a paycheck. In the mean time, you'll pay for your business cards, For Sale signs, open house signs, MLS fees (mandatory membership in many places), desk fees, NAR fees, CRM/tech fees, gas and mileage and for all of your own marketing costs - which can be crushing. And let's not forget paying for your own health and dental insurance.
You'll walk in the door with your shiny new license and have to pay all those costs - with no income.
Everybody and their brother is looking for money from you. The worst are the likes of Zillow, Trulia (owned by Zillow) and Realtor.com. They'll sell you leads at a very high cost - but unless you buy a crazy expensive program, 4 agents get the same lead simultaneously. You had better be the first one to call or your chances of success are very, very low. That means responding within 30 seconds. Day or night, weekdays, weekends and holidays. By the time the third or fourth agent calls, you can bet that the seller is going to be getting testy.
Even if you do get the listing appointment, be prepared for the competing agent to promise the seller that he can get a higher price than you can. If you've run your comps right, that won't be true, and the seller will eventually figure out that you were right - but you will have lost the listing.
Even NAR says that 87% of agents are out of the business within 5 years.
On the bright side, if you can stick it out and grind *hard* for 5+ years, you should start to see some referrals and repeat business - but you have to ask yourself, "is this the best use of my time, money and effort?" Or would you be better off with a W-2 job?
Sorry to sound so negative, but that's my experience. I really want prospective agents to have a realistic idea of what they're getting into.
Whatever you decide, good luck!