You can join them together using a mixer circuit. See my thread on sam’s stripboard design:
You are also going to want to power it. If you want you can build your own power supply. Link here for reference as well:
If you just want a simple project cause its all intimidating, just do like sam said and use some batteries! A lot of us here are beginners learning. There are also plenty of experienced folk.
If you have any other questions just ask yo.
Dont be scared to try it!