Good advice from imafan. Definitely start your own compost pile. That won't help you right now, but by fall you will have some of your own homemade compost (for free!), that is the best thing you can add to your garden. Browse in our Composting Forum, if you aren't familiar with it.
Starting a garden doesn't have to cost tons, but there is a bit of initial start up cost. If you are going to box in your raised beds, it will probably cost you something in materials. As imafan said you don't have to, but if you are buying or making your own soil, the box contains it, so it doesn't wash away. If it is on top of native soil, it only needs to be about 8 - 12" high. My raised beds are built of pine fence posts (4"x4") which are cheap. Other start up costs will be a bit of tools, if you don't have them already. Essentials are trowel, shovel, hoe. Others can be added as you need them.
What to put in it: start with good quality topsoil (NOT fill dirt) and mix in some combination of compost, mushroom compost, well aged composted manure, peat moss, leaf mould (broken down fall leaves), maybe a bit of perlite or vermiculite to keep it loosened up and draining, other organic materials as they are available to you.
re: Things like blueberries, strawberries, raspberries, spinach, lettuce, kale, tomatoes, carrots, potatoes (sweet or white). You need to study up how things grow. You have a somewhat short growing season and it looks like not lots of hours of sunshine. Put your beds in the sunniest spots you have. Blueberries grow in bushes and they need acidic soil (where that soil test comes in). The bush once you plant it will stay there, so you don't want it mixed in with your annual vegetables, that will get dug and replanted every year. I have raspberries which I am in the process of (painfully) ripping out (they have stickers). The birds get the berries and they spread very fast from the roots and from seeds the birds drop. They are taking over my yard. Strawberries would be good. They also are permanent and need their own bed/space. You won't harvest any this year, but you should next year.
For me it would be too late to plant spinach and lettuce - once it gets hot they bolt and go to seed. But it looks like your climate doesn't warm up very fast or get very hot, so maybe, if you get your beds together quickly. They are usually grown from seed planted directly in the ground and they are quick. You can be eating baby spinach/lettuce in about 8 weeks. For greens, kale and swiss chard are easy to grow and last longer in the garden.
For getting started without much experience, the easiest thing would be to go to a good local nursery and buy a few well started plants, probably tomatoes and peppers. One 8x4 bed is about room for 3 tomato plants and 3 - 4 pepper plants and that will be all you need. It is too early for you to plant them now, but by the time you get everything together, it will probably be time. Tuck some basil plants around the edges. Potatoes and sweet potatoes are trickier and need special conditions. Get started with other things first. It is too late to grow broccoli from seed, but if you find some well started plants, you can put some of those in also. Look for onion sets (which are baby onion plants). They don't take up much room, you can put them around the edges of everything else, and they are good companion planting to help keep bugs away from your veggies.
Everyone and every situation is different. But personally for a couple raised beds, I would never bother with an irrigation system. Looks like you get plenty of rain, so you won't even be watering that often. It isn't hard to water that little bit of garden with a hose or even carrying water in a watering can.
Here's a vegetable planting guide for Novia Scotia: https://homeharvest.ca/PDFs/Planting%20G ... %20web.pdf
Come back and ask questions as you go along. Good luck with it, you are starting a great new hobby!