I'm taking an online course right now to get my RE license. What can I realisticly expect when I get my first job? What kind of costs are there? How do you get your first clients and get started? How long can I expect it to take for money to start coming in?

Honestly? You may have to wait a LONG TIME for money to start coming in.

I should mention that the money right now is the least important thing to me. I have a job that I will be keeping that pays the bills, so this will be a part-time gig.

Read as much postings on this forum as possible.
There's alot to learn. Spend alot of time on here.

Costs vary depending on what you want to do, what you want to spend, and of course the expenses that you'll definately need to figure in. Also, might depend on the company you sign on with.

As for money to start coming in, this will vary on the individual. Starting making contacts, build a database of everyone you know. Do a search on this board for "Sphere of Influence", "database", "leads"....
I am sure you will find plenty to read up on.

good luck

A lot also depends on geography. Fortunately, you are not in an area where the market has been crazy and so you are probably not experiencing the agent glut that I am.

Expect your first year to be a loss, maybe even your first 2 years because you will be part-time. There are many expenses that go along with this business. You will put out more money than you will probably make at first. If you are good with talking to people, then just hang in there and things usually get better. Always look for new business. Take every opportunity you can to talk to people (the public) about real estate to try and gain future clients.