Please do some research, maybe some of the quiz links - let us know what they came up with for you.
Please do not get your new dog from a pet shop or an add in the classifieds (online or not), if you're not sure if an ad is legit, post us a link and we will check it for the battery puppy farm / puppy mill warning signs. Why don't you want one of these? Because they often have health problems, both mental and physical because puppy farmers are not usually the least bit interested in the health and welfare of their dogs, or they wouldn't treat them the way they do.
This site has three links you need to read including a puppy buying guide.
Help end puppy farm horror | RSPCA Australia | For all creatures, great & small.
other helpful links.
This one has a great quiz about your lifestyle and needs in a dog and matches you up with a number of breeds and tells you why a dog would or would not suit your lifestyle. Note - not every dog of a particular breed has the typical breed personality so you'd need to make a personal assessment of the dog in front of you.
Matchup: Your dream dog | Dog Time
put firstname.lastname@example.org at the end for your email if you just want to see the results online. And it is a USA based site so you can't really adopt the dogs they have on their site (quarantine problems)
This one has how to choose a rescue dog.
This one has how to setup, prepare and look after your puppy.
Digital Dog Training Textbook | Dog Star Daily
Remember there is puppy preschool at your local vet, and then puppy obedience classes etc. If the place trying to sell you a puppy doesn't have anything to recommend along these lines - go somewhere else.
And then there are the basic law and order issues - depending on where you live, but your local council website is a good place to start for finding out your responsibilites when it comes to living with a dog and keeping your neighbours sweet.
It might seem overwhelming, but just read a bit each day and build up to it. Don't rush, there are plenty of puppies or dogs out there. You don't want to be returning yours later because it wasn't really what you expected.