Listen, I am no expert, but I have been carrying since October 2010. I can tell you that "what to carry" is as unique to each person as their choice in underwear.
For example, I carry a Glock 17 Gen 4, a Taurus PT111, and a Kel-Tec PF-9. Each of these firearms are carried when a clothing situation is dictated.
When I have winter attire, no question it's the Glock. When I have jeans and a tshirt, I carry the PT111. When I have shorts, I carry the PF-9. But that isn't always the case.
Where you go, what you do, what type of exposure you are comfortable in showing (or as your state laws allow) will dictate what you wear and what you carry.
Some times I have the Glock in the truck in a lockbox, while I carry 1 or both of the other 2.
As for which firearm suits you, you need to find a range that rents the types of firearms you want to research or own.
That is the best way to determine what you like, and what you are comfortable carrying in Condition #1.
(A loaded magazine, with a round in the chamber, ready to go)
Since you expressed a budget concern, if you have friends who shoot/own/carry the firearms you're most interested in, ask them if they'd go to the range with you to shoot.