Commercial ammunition will state the weight of the bullet on the box, such as 125 gr. HP (hollow point). They won't tell you the weight of the charge of powder or the type. Sometimes the velocity obtainable will be printed on the box. If a cartridge is labeled +P it means it is loaded to a higher pressure and should have more velocity. How much more depends on the gun you are shooting. There will be variations in this information due to barrel length and some other factors.

An example would be: 125 gr JHP +P, which means a 125 grain jacketed hollow point bullet loaded to a higher pressure than standard ammunition.

Workable bullet/powder combinations for different calibers are found in books for people that make their own ammunition, like many of us here do.

Don't worry about the questions being 'elementary'. Do some homework and you'll learn fast. And if you are willing to help yourself, there are a lot of knowledgeable people here to help with the parts you don't understand.