I'm baffled.
I did hear mention of Spotlight once before, but never in terms of being a requirement to register with any other agency. What sort of work as an actress are you looking for, film, TV, or treading the boards?
I do supporting artistes work on TV and film and I've never had any training. OK, the pay is a a bit of rubbish (about £100 per day) and you don't get your name in the credits unless you're in Equity or something like (read further down). And from what I know, Equity won't reject you for not having a SpotLight number.
Where do you want to start as well?
Start working as an extra and at every oppotunity try and get yourself near the Director's chair when you aren't required on scene and they don't send you back to the Bus. That way you can see what's happening on his monitor, which is interesting and (this is a bit sexist, mind) he might take a fancy to your looks and give you a line of something. Well, if you've got it flaunt it girl.
Of course you could end up with a female Director but who knows in this modern day and age. 
What I'm suggesting is all innocent, but that's how a lot of work gets shoved around. The thing is you learn how the scenes are stitched together, one day you're working on one scene and next week you're working on a scene that takes place before the scene you worked on previously.
I did a Foyles War in 2006. On the Monday we did one scene and on the Friday we did a scene that appeared before it. They told me to let my whiskers grow and look scruffy, as a war time factory worker hence -
Yeh, no prizes I know, but I got extra money for that and had a 1940s haircut and then they slapped on some make-up dirt. Still the grub was good and we got extra pay again for working on a Good Friday.
I have done a few speaking parts, one was playing Joe Mears (Secretary of the FA) in 'Who stole The World Cup?', a documentary for Channel 4. It was only a small part because the real Joe Mears got taken ill soon after the Cup went missing. However, when it came to the credits my name wasn't up there, but my character's wife, Mrs Mears, only had two lines and her name was on the credits - because she was an Equity member.
Get back on to Ray Knight and see if you can speak with a John (I forget his second name) or Tony and just ask how do you register. You'll have to go along there and take your pictures or they'll take their own, fill in the form and your on their books. It's £35 + VAT per year and you don't pay up front, they take it out of your first booking fee and a 15% commission charge on every booking.
It has to be worth it for the experience and the exposure. Speak to other extras and they'll put you right, there' some really nice folks doing it.
Good luck and send a message if you want to discuss further.
Lovely shot, should interest a model agency, well done you!
