to my knowlage it is done both ways... the recruiters would be better at telling you exactly how it is done. but there is always going to be a component of your basic courses that will be run over the summer. with a service battalion.. ok.. with our unit there are a couple of trades, the cool ones are MSE-OP aka Trucker, and Vehicle Tech, aka Parts changer, you also have supply techs, and clerks.
so i‘ll give you a little info on each trade.
MSE-Op as a trucker your primary job is to operate and maintain, our fleet of trucks. essentially you are the UPS or Purolator driver of the army. nonetheless its a pretty cool job, and we try to have alot of fun when wer‘re out there.
Supply Tech: If you dont become a Sup Tech, at least make sure you are freinds with one. these guys and galls issue all the wonderful wonderful kit the CF supplies to each soldier. this job is gonna involve alot of sorting and such.. lots of paperwork. but you will also get to drive a bit as well.
Veh Tech. You fix broken trucks. Pro‘s: Excellent trade to learn and very practical in the real world. Con‘s: it takes a long time to get qualified and learn your trade.
Clerks. also not the people you want to make mad.. they do alot of thankless duties that you dont even know about. they also work out your pay, and do the paperwork for loading you onto your courses etc...
Im pretty sure thats all of them for our unit..
any of the trades are good. go to the DND site or the recruiting center and read up more in depth on the trades, and pick the one you think you will like the most. 23 svc Bn is a really good unit with some really good people.. its definatly a good place to work.