I'm not sure of your background, so here's the basic form it takes...
To become a FOO you must first pass officer training, DP1.1 (mostly recce for Field and Air defence deployments)and 1.2(Bty level Recce and gun line Ops, including some Command Post work), spend time on the gunline in a Regiment, then after some experience, maybe on tour, and courses to learn some basics on Tactics and the operating in the LAV OPV (Artillery variant of the LAV III) you will go through a 2 phase FOO course, mounted and dismounted Ops. This will only give you the basics after which the battery commander will prepare you for actual Ops and, if you're lucky, a tour as a FOO. An officer's time as a FOO is short though, they quickly move onto other staff work, regimental or otherwise, maybe returning to the OP world as an Instructor of Gunnery (following a year long course and a few years more in the school) or as a BC years later.
On the other hand if it's working in an Observation party that you really want to do, then consider that some NCM's spend virtually the majority of their career there. They way this works: after a bit of time on the guns (about a year) should a gunner let it be known that they want to work in an OP, and their chain of command supports it, then eventually they'll be sent to work in an OP party, usually as a signaller, maybe as a driver at 1st, to see if it really suits them or not, then on to the OP tech course, where they'll learn some basics on how to shoot. In addition there'll be courses on how to be a gunner in the LAV OPV. Following some time in as a tech, and the Primary Leadership course, they'll make it to OP Det commander, and take the course for that (which is basically the FOO course for NCM's, primarily on how to read a situation tactically and provide advice to the supported arm commander, and then coordinate the effects of the different delivery systems. It's a lot more complicated than that explanation sounds). Because it takes so long to really master being at the OP, the Artillery has gone to "streaming", ie once you go into the OP stream you will not leave it until you're a Warrant Officer.
Your call but in the meanwhile get the basic soldiering skills down first, crawl, walk, run eh?
You have a long road ahead of you, but keep your head up along the way