Hello Jimmy,
First thing - well done on getting out there and getting stuck in. With a bit of grit and determination you'll get the necessary results.
Without knowing a lot about you, your current state of fitness, exercise history etc, it's very difficult to make specific advice on your training. But there are a couple of general points that I think would help.
First, for most people the 1.5 mile test is primarily a test of endurance. As a newcomer to exercise, the best way to train for it would be to follow a 5km or 10km running programme. Try Runner's World (other running websites are available).
Second, get out and train with other people (and possibly get some coaching). Join a local running club and go out on some of their club runs. You will be amazed how quickly your pace develops if you are regularly running with other people. You will naturally find that you are doing some longer, steady runs (really important for the 1.5 mile test) and some shorter intervals and hill work.
Lastly, try and find a session that allows you to develop your all-over body fitness. Circuit training is good, but there might also be a football, boxing, or rugby club locally that has a "fitness session" that you can join in with. Anything that has you pushing yourself to do lots of bodyweight exercises etc. Again, it's good to train on your own - but you will push yourself harder and learn more if you train with others.
Good luck and all the best,
Andy
PS - Having said it's difficult to give specific advice, I'd strongly agree with Phirstman. Your training is missing a long, steady run - at least once a week - building gradually to a 60-90 minute effort. It will pay massive dividends on a 1.5 Mile test.