A good bike shop, with knowledgeable staff will certainly make finding the right bike for you much easier. The problem is that not all bike shops have competent staff. You can like to ride bikes, or you could be great at sales, but neither of those qualities benefit customers, especially new cyclists.
Budget considerations, riding goals/intentions, and fit are the key things here. Before you set foot in a shop, determine what you are willing to spend. It may very well be that your budget won't accommodate the bike you want or need. What will you do then? Revise your budget, seek out a used one, or look online for something more affordable? Whatever you do, don't feel pressured into spending too much. It's not like they only have that one bike at that price, and it will be gone tomorrow. And I guarantee you, someone in your city/town spent a lot on a bike that they rarely rode, and is listing it on Craigslist at a very reduced price.
Do you want to ride just for fitness, or get really competitive? Are your roads beat up or smooth? Will you be climbing hills, or do you live in a flat state? Will the bike be used for commuting? Running errands? Maybe a little shopping? Or strictly sport?
Fit should not be overlooked either. People come in all sizes and shapes. Torso length, arm length, leg length, and flexibility all need to be considered when it comes to fit. Just finding a bike that doesn't smack your crotch when you come to a stop isn't enough. Whether you ride for fun or competition, you'll want your seat at the right height, with the fore/aft set properly, and your handlebars will need to be at the proper height, along with the correct stem length. Rarely does any bike fit perfectly out of the box.
But we're here to help, and make it all easy to understand.
