Stephen makes the most valid point that can be made. I can see from your CV that your experience of working outside of training appears to be non-existent and so, perhaps, your uncertainty about the process of applying for work is understandable. Honestly, however, I'm a little concerned about what your teaching was like if you have been left with no awareness of what steps you need to take in order to secure small scale jobs following training. Applying to work in fringe theatre works on *exactly* the same basis as applying to work on any production, at any level, anywhere. You locate the casting breakdown, write a covering letter introducing yourself to the prospective employer, make sure to include an up to date CV and headshot, plus optional extras like showreel material if required, post the application and wait until an interested party arranges an audition with you.
This method applies if you are working as a jobbing actor from home, or if your top flight agent is sending out the applications on your behalf to the cream of the industry. A site like Casting Call Pro takes the sting out of the process by allowing you the opportunity to easily reply to breakdowns directly online, and to allow an instantaneous link to your hosted CV, so you don't have to send it separately, but the practice is no different. The only actors who don't apply for work via these methods tend to be very well known and respected within the industry, and to have agents who can pull strings in order to get them seen personally for negotiated meetings with directors/producers. But even here, there's a linked logic: these actors tend to be so well known to the people hoping to cast them / come so well recommended, that there is no need to go through the preliminary stages of assessment that an 'unknown' actor needs to.
If you are offered an audition, then you try your best to come up with whatever the audition panel asks you to - whether that's preparing a speech of your own, learning an excerpt from the play that they're interested in, coming prepared to 'cold read' or whatever.
Obviously, as most true fringe productions are badly paid/not paid at all, the majority are of little interest to agents. They therefore tend to source talent massively from sites such as this, similar online websites, through advertising in PCR, on The Spotlight and so on. Some source cast through recommendations or suggestions made by other members of the company.
As Steven said, with some surprise, if you are already signed up to CCP, and paying for the use of the forums, surely you have some idea of how the application system on the site works? And while a considerable amount of work offered *isn't* fringe theatre, a vast amount is!! I trust you've not been confused by the division between 'Jobs' and 'Opportunities' that CCP upholds; 'Jobs' are paid work, and 'Opportunities', unpaid - but as you are mainly looking for fringe theatre, which is about 98% of the time unpaid, it will be listed not under 'Jobs' but under 'Opportunities'. I think it's true to say that there is generally something like two and a half pages worth of breakdowns for fringe theatre released on this site daily (at weekends, of course, the site isn't updated).