How do I join meshes to other meshes??? 
It’s not too hard to check the hotkeys menu, or there are a lot of other places to find it on your own. I did a quick search of “Join and Meshes” and came up with two other answers to the same question on the first page. Search is your friend and it saves time for you and the people that post answers. Anyway, you select the meshes you want to join and press Ctrl+J to make them one object. If you actually want one to physically join the other, you can use the interect Boolean modifier.
or you can merge them one verticles at a time… (w then merge at anything but cursor)
or you can go 4 verticles at a time and use the f key
I usually use the f key…