Gardening for beginners

I'm in Michigan zone 5a so it sounds like your area will be a bit warmer.

1. Make sure you know your soil type. Do you have clay, normal soil, loamy, or sandy soil?
2. Make sure you know how much sun each area of your yard gets. This determines which plants will do well there. Most plants that produce fruit (tomatoes, peppers, berries, etc) or edible tubers need full sun.
3. Check your plants every day to see if they need water. Never water unless the top 1" of soil is dry. Put your finger in to test the soil. Over watering can kill your plant.
4. If your plants are drooping (and they don't normally droop), they need water. Do not over water, it will damage the roots, so the plant won't get water, and it will look droopy too.
5. Windy days can remove lots of moisture from the soil, be sure to check all plants on windy days too.
6. Heat can also remove moisture from plants so use mulch. Since I live with loamy soil, and we get no effective rain in July and August each summer, I have to use mulch and an automatic watering system. Sometimes plants need water twice a day, it gets so hot, and I'm simply not at home all the time to do so.
7. Get the right plant for the amount of sun and soil pH.

What's your gardening zone and soil type? Does your soil have a lot of clay? Most plants need something that drains well. Or is it more normal soil with a good amount of organic matter? Or is it more loamy or sandy? Loamy or sandy soil does not keep moisture well so you need to add 2-3" of organic material to the top layer, then cover with mulch.
The mulch will break down and the provide more organic matter.

DIY devices

1. Cut the bottom off a 2 liter bottle, put the cap on, poke 4 holes in the cap, invert it and stick it in a 4-6" hole in the ground. Put a few rocks in it so it won't blow away in the wind. Fill with water and now you have a slow, deep watering device.
2. Battling cutworms. Cutworms especially like to much on seedlings outside. To deter them, cut the bottom off a plastic cup, and put this ring around the plant before the plant gets too big. Make sure the ring is at least 1" above the soil.
3. Battling squash vine borers. Put a strip of aluminum foil around the base of the plant before the moths arrive to lay eggs. The foil seems to confuse the moths so they won't lay eggs on that plant. If you do find a SVB, piece it with a needle.

Easy flowers for beginners

1. Daylily. They can store some water in their roots so they can go 2-4 weeks without water before they droop. This is not an excuse to ignore your plants though. This just means they are good for beginners who sometimes forget to check the plants. They also multiply like crazy so you can spread them to other parts of the yard. These look like a clump of grass with thicker leaves and come in a huge variety of colors. These can be divided by jamming a shovel in the middle of the clump.
2. Liliums are a lily that grows on a single stalk with a nice bunch of flowers at the top. You can leave them in the ground in the winter. They are also a bit tolerant of water neglect but not as hardy as the daylily. These can produce baby bulbs that when they reach 1" in diameter, can be transplanted to a different location. They come in a huge variety of colors. Easter lilies are related to these but cannot survive winters outdoors.
3. Tradescantia (spider wort). This is very hardy. Two wild colors I have are blueish and magenta. They come in other domestic colors like white. They also have tuberous roots which they use to store water. They might die back in the summer but will come back in the fall automagically. Image here. They look a bit like crab grass so be sure what you have. Key points: 3 petaled flowers with bright yellow pollen thingies.

Easy veg and herbs for beginners

1. Garlic, onion, leek. Put the bulbs in the ground after a couple hard frosts, before the ground freezes, and they will come up just like daffodils in the spring. In the summer the green stalks will brown and die, but will likely return in the fall. I have "Egyptian" onions, aka Walking onions, or top onions, which are very hardy and spread easily. Top onions have a very mild taste. They grow bulbs underground and small bulbs on top which can be used for martinis, or baking or slicing. If you're in West Michigan I'll give you some for free.
2. Chives. Same as onions. Easy to grow from seed so it's good for kids. You don't have to thin it necessarily like other plants grown from seed. Easily grows back when you trim it.
3. Zucchini. Keep it watered and it does the rest on autopilot. Pick and eat before the zukes reach 10" in length otherwise they get seedy.

Intermediate veg

4. Pumpkin. There are some fun varieties of pumpkin like a mini white one called Baby Boo and other names. It does need richer soil, it won't do well in loamy soil. Make sure to water it when the leave wilt, which will be every day in mid to late summer. Easy to grow from seed.
5. Squashes. Similar to pumpkin above.
6. Cucumber. Similar to pumpkins. Cukes, squash, and pumpkin are all called cucurbits.

Difficult veg/fruit

1. Watermelon. Uses a LOT of water, must be watered every day, does poorly in loamy soil, needs some organic matter in the soil. The single watermelon I grew and ate cost me about $40 in water, fertilizer alone. It can be fun, but it's not cheap.