Generally "reaching deep within" is a rather artistic way of saying trying very hard to accomplish something. The thing your reaching for is strength, strength that is inside you. Maybe you didn't know you had it, or you have to struggle to bring it out. The first sentence sounds strange to me, it's not clear. Like it might be a line in a poem or a song. I would guess that the "first hello" is referring to the memory of the first time "you and your friends" met each other, and it's deep inside you because it is a memory from long ago. For what reason you would "bring back" that memory is unclear. The second sentence doesn't have anything to do with the idiom, "reach deep inside". Here global reach is a separate concept from deep knowledge. Global reach is refers to how much their company has international service or customers. Deep local knowledge refers to how much they know about the local area, (here we can assume that knowledge is most about business). So they combine knowledge about where they are now, and extend it to other places across the world.

1) Reach within yourself- It means to remember, to search your feelings, or to search your past for a feeling or moment you once had. 2) Deep knowledge- in depth knowledge about a subject; strong knowledge; adequate OR abundant knowledge. I hope this helps you a little bit!