I adore dogs and always have them in my life. That being said, they are similar to a child and need more one-on-one time than, say, a cat. Dogs need far more exercise than a typical cat given that they have been bred to work and are bigger and have more energy to expend. Some breeds are less "needy" than others and prefer to be couch potatoes but most dogs are not like that and require daily walks. If you're worried that you wouldn't be able to keep up with that, get a smaller breed who can be worn out easier (not a terrier), but if you enjoy walking then bigger breeds work well. But they need training. You have to know at least somewhat what you're doing to properly train a pooch, especially to avoid them jumping on the wrong person or pulling you to kingdom come as that can put them in serious danger.
Dogs also require a lot of mental stimulation to avoid boredom (and consequently behavioral issues like chewing and barking) as they are very intelligent creatures. It's fairly easy (and fun!) to do this with puzzle toys (diy or otherwise) and fun games when you feed them. I love to hide food for my dogs to nose out or stuff a Kong with wet food, rather than just putting everything in a bowl.
Living with both cats and dogs (among other animals), I definitely have a greater affinity for dogs, particularly the big ones. They're usually lovable and loyal and sometimes a bit clingy. I've been training dogs for the greater part of my 27 years and believe in positive training over any other method. I've got a couple of blog posts here about my dogs and I think All About Cocoa really encompasses what it's like to have a dog. More to come in the future!
Watch It's Me or the Dog on YouTube to see some of the common behavioral issues and how to fix them. It's a very informative show and has helped me train several dogs (two chocolate labs, a GSD mix, a Black Mouth Cur, and by proxy an Australian Shepherd mix; all big dogs). Consistency is key to dog training. Consistent in your rules (like being allowed on the couch), the words you use (don't use 'down' one time and then 'lay' another for the same command), and have set hand motions when you do give them commands. Because it's not only cool af to not say a word and get your dog to do tricks, but also if they go deaf you can still communicate with them.
And be prepared to be utterly devastated when the inevitable happens and your beloved pooch passes away. My old lab passed almost two months ago and I still cry about losing him.
Hope this helps you make a decision! Feel free to ask questions if you have them. I could rant about dogs all day, lmao ♥♥