Dogs and a life with dogs is fantastic!
You need to go into it completely aware of the commitment you will be making for the next 10-15 years and this the right place to ask because posters will try to put you off getting a dog and if you come out the other end committed, determined and still keen then you might just be a doggie person! You should approach this thinking about what you can give a dog rather than what a dog can give you.
Lets start with the commitment -
Dogs need exercise for physical and mental stimulation or they are going to get bored, depressed and possibly destructive. That means a good walk in the morning, afternoon and evening come rain, hail, snow, dark nights for 10-15 years - at least one of those daily walks should be > 1hr and preferably off lead. In summer it is tough because they cannot go out when it is too hot as they easily overheat and concrete gets too hot to walk on. So summer walks tend to be very early morning and late at night when it is cooler, or if you are lucky to be near a dense wood, that is a good place to walk as cooler/out the sun. They will come home from winter (and autumn and spring) walks wet and caked in mud (if it is a decent walk for them!). Your small garden will not be enough for exercise or mental stimulation or a alternative to walks in all weathers, the garden you previously enjoyed will become your dogs toilet - if you have grass it is likely to be ruined.
Dogs also need mental stimulation. The generally means training. Training is continuous throughout the dogs life, more intense in the first 6 - 18 months through the puppy and stubborn teenage phases. You will need to teach strong recall so you can let you dog off lead to exercise, this training of recall never stops and can be easily lost and difficult to recover if you become complacent.
Dogs are expensive. Insurance will start cheap. By the time our dog was 10 years old it was £100/month. But imo needed, a consultation with the vets can be £60-£80, an overnight stay for something minor like vomiting can be £400-£500+. Emergency vets in evenings and weekend hundreds of pounds. Prescriptions are expensive. Monthly flea and worming is expensive too £20/month+. Decent food will set you back £40-£50+ a month. Add in walkers and if you are going for a dog that doesn't cast regular grooming costs.
Dogs are very restrictive. You can no longer go to weddings, funerals, holidays, days out without always considering the dog first. You also need to spend as much time training your children how to behave around a dog as you do the dog - young children should never be left with the dog unsupervised - so if you are all relaxing in the garden and you want to pop indoors you get into the habit of taking either the dog or the child with you.
Dogs don't always behave the way you want/expect. You could have issues - some very common ones are house training, excessive barking, resource guarding, separation anxiety, health issues. You cannot guarantee a dog that "enjoys children with a gentle temperament" - that is partly nature partly nurture - our very placid Labrador wasn't great with ds(9 at the time) when we first got him. All can be very time consuming or expensive to try to improve (some can never be fixed only managed).
After all that......still love dogs. We lost ours to cancer last year and I am now desperate for another, but I know even though we have the experience of dog ownership we don't currently have the lifestyle for the intense puppy first couple of years or settling in a rescue dog. Will need to wait until I retire in 5-6 years time.
Keep researching, and just make sure you 100% know what you are letting yourself in for as many people don't do their homework and regret it.