Hi bebo and welcome to NAPM.
I think there is quite a lot you can do without Spotlight entry. You are quite right that it is something you will need, but you can work towards it - it probably won't be a quick process though. If an agent is interested enough in you then they should be prepared to accept you without a Spotlight entry, on the understanding that you will get Spotlight entry as soon as you are eligible. On the other hand, the agents may say "come back when you have Spotlight entry and a bit more on your CV" or they may very well say "let us know when you are in something we can come and see".
It is quite possible that you will be accepted for membership of Casting Call Pro. Although they do stipulate the same entry criteria as Spotlight, they don't seem to be as...umm....robust...in checking applications. With membership of CCP you can then apply for paying jobs (though there aren't many) on their site. You could also (if you've got enough money after paying for CCP

) join Castweb who regularly carry a lot of very good information about paid work - particularly commercials. Getting some featured work in commercials may be your best route to Spotlight (not that it's easy, but it's possible) because CDs for commercials tend to call in quite a few people for auditions and don't particularly mind if you have no representation.
You are very unlikely to be able to get any paid TV or Film work without an agent.
You can also research small scale theatre companies. They often have websites which give details about how they go about casting.
You can consider trying to get a showreel together - this can be a very good tool to interest agents (and, once you are in Spotlight, Casting Directors). Apply for as many student and low budget films as you can - or you could consider paying for a "shot from scratch" reel - do plenty of research though because some of them are dreadful!!
I recommend getting the Actors Handbook or Yearbook (whatever it's currently called). You can get previous years' second hand copies very cheaply from Amazon market place. There are lots of contacts in the book but also some very interesting and informative articles for people just starting out.
Simon Dunmore's, "An Actor's Guide to Getting Work" could also be useful. Also, "Make Acting Work" , Chrys Salt and "So You Want to Tread the Boards" - Jennifer Reischel. They will all give you more information about how the profession works.
Work is really, really, really hard to come by

. I know some truly wonderful actors who have trained at top drama schools and who have agents who haven't had a single acting job so far this year...