You could use a breadboard to create a "bus" for distribution of the RPi's +5V (or +3.3V) power to your "add-ons". You should understand which sockets/holes on the breadboard are common before you get too far along with this. You should also keep in mind when patching connections from the RPi's GPIO pins that many of these pins are "electrically fragile", and the RPi is easily destroyed through wiring errors. The Raspberry Pi GPIO pinout guide is a good resource to have at hand.
Read the information in the breadboard link above. I think it will show you how the breadboard is built. Pay particular attention to the figure below as it shows the patterns of electrical connections. For example, if you connect your +5V pin from the RPi to a hole in one of the 4 "bus strips", then all the other holes now have 5V on them also. You can then power your "add-ons" from another hole on that same bus.
Some who are starting as you are use a tool called fritzing to plan their wiring layout. It may be of some help to you. There are videos and tutorials available.
Finally, keep in mind that the +5V (and +3.3V) power outputs on the RPi are limited in terms of the current they can source. The pinout guide linked above supplies some estimates as to their current limits. This suggests that you may need a "budget" for powering your "add-ons".