Lakes around Vancouver like Lafarge will be stocked again in mid September (depending on how hot the weather is) so you only have a couple more months to wait until you get another chance.
That being said, if you give these lakes a go in the evening time, you should still be able to catch some. Lafarge is pretty heavily fished so the fishing would in fact not be as good as some of the other lakes around here. It might be worth trying Buntzen and Sasamat in Port Moody, or Alice and Edith in Squamish, or Lost in Whistler. The setting at these lakes is also nicer, not that Lafarge is bad, it's just a bit urbanized.
For salmon, it's never too early to start since we do have plenty of them around during certain time of the year. The learning curve would just be a bit steeper than urban trout fishing. Ambleside and Capilano River mouth are definitely a good bet for the rest of this month and August, but you need to be there early in the morning. Your chance is also bigger if a outgoing tide coincides with sunrise. Get some spinners, buzz bombs and make sure you have the appropriate rod and reel that allow you to cast far and handle these fish. Your trout fishing setup might be adequate for smaller coho salmon, but it can be too much of a challenge on large coho salmon and chinook salmon if you encounter them. Light tackle can also be too stressful on larger salmon if they have to be released in the end.
For coarse fish, it does not hurt to try that either. After fishing for salmon and other what most anglers regard as "elite" species, I still enjoy wetting a line in the Fraser River on a hot day like this. The action is constant, it's relaxing, it's close to where I live, so can't really complain.
Good luck.