I googled and found your local newspaper has a gardening column, so that's probably a good place to start researching what to plant when in your climate. It sounds like it's still quite cold there, so it's a good time to start doing soil prep and figuring out what you'd like to grow. I agree that lasagna gardening is a good way to get started. You might also want to do some reading about apple tree care -- pruning, thinning fruit, organic pest prevention, etc.

The best thing to grow is whatever you like to eat! If I were starting out, I'd look for a good garden center nearby. "Good" means that the employees are knowledgeable and can answer your questions, and that they stock varieties that do well in your area. If there is a gardening club, or if you can find neighbors who are eager to give advice and share seedlings, even better. Though you may eventually want to start all your vegs from seed, I think it's a good idea to get a few seedlings of warm-season plants such as tomato, pepper, and eggplant/aubergine to start, if those are plants you want to grow.

When I started gardening, growing seedlings into mature plants was enough of a challenge, and I think early successes are important to encourage new gardeners to persevere. Getting from seed to seedling takes extra time, and the emerging seedlings are more vulnerable to insects, birds, and changes in weather.

Beans, peas, cucumbers, and squash/courgettes are not hard to grow from seed, but you may need a place to keep them protected from snails/slugs and possibly weather for a couple weeks or so. I still buy transplants of some of these if the garden center has varieties that are hard to find as seed. I won't even start my seed for 2-3 weeks at least.

Leafy greens such as kale, and cool season vegs such as beets, are fairly easy to grow from seed.

Depending on your climate, many herbs are perennial and drought-tolerant and can be grown among landscape plants. It's nice to be able to snip a sprig of oregano or lemon balm from the garden.