What everyone has described above is technically true; however, it represents the extremes. These things (particularly separation) can be mitigated. The fact that the CF may not move your family at public expense does not mean that you will never see your family while you are on training or awaiting training. While on BMQ/BMOQ you won't have time for anything, but the course, so not seeing your family at that time is a given. However, after you've finished that, you can likely take some leave before the next course. While on trades training you may have opportunities for your family to visit (stay in a motel and you visit with them on evenings or weekends). This mostly depends on how much money you're willing to spend and how heavy the course load is. There are sometimes opportunities for PAT personnel to spend their time waiting at bases that are closer to their families (no guarantees, but it does happen).
If you go into a hard sea occupation, there is a strong possibility that you may be sent to Fleet School Esquimalt for training (you should ask which courses are only offered at one Fleet School or the other), so you would be close to home there. Another thing to remember is that most hard sea trades have a "Home Port Division" (HPD). If you are selected for HPD West (again, no guarantees, but you are allowed to state a preference), you can spend the bulk of your career in Esquimalt. HPDs don't mean that you will never serve anywhere else, but they do tend to avoid the cross-country (Halifax - Esquimalt/Esquimalt- Halifax) postings we used to do every few years.
Finally, ships seldom deploy for more than six months. Also that is six months away from home, not six months at sea. There will be port visits and maybe even opportunities to go home on leave during the deployment (not always, but possible and there may be financial assistance to help with costs). In almost 30 years in the Navy, I've never seen or even heard of a ship's deployment longer than eight months (and only one of those at that - it was a special case). Furthermore, we only send one ship at a time on these long deployments so sailors go for years without making those trips and some never make any at all due to their posting cycle.
Perhaps I'v given you the opposite extreme of what some of the other doomsayers have said, but in my experience, my description is accurate. Perhaps the real truth is a bit more between the two. The bottom line is that many things are possible and there are few guarantees, but I don't think you have to accept the idea that you're not going to see your family for two years. There will be opportunities. It will be up to you how you take advantage of them.
One last thing to keep in mind is that there are some benefits designed to reunite you with your Next of Kin (NOK). Once per fiscal year (1 Apr - 31 Mar) you are entitled to Leave Travel Assistance (LTA). This is a subsidy (i.e. doesn't necessarily cover the whole cost, but it can) designed to help you get home. A key point is that it can be used once per fiscal year. This does not mean you have to wait a year between uses. You can go home on leave in February and then do it again in May of the same year if you like (NB: assuming member is not on TD where some additional caveats apply, but member on PAT is not likely on TD). When deployed for more than 120 days, Home Leave Travel Assistance (HLTA) applies, which is separate from LTA and more lucrative. Also, the CF has Christmas flight program which can be used to get home at Christmas time. This program gives priority to married personnel separated from their families and using it enables them to save their LTA entitlement for another time.
In short, life is not necessarily a bowl of cherries for those in this situation, but it's not necessarily the pits either.