You can call channels->list with "part=id & mine=true"
GET https://www.googleapis.com/youtube/v3/channels?part=id&mine=true&key={YOUR_API_KEY}
Id is the channel's ID.
You can get the video's title from the response under [snippet.title]. You can get the channel's title from the response under snippet.channelTitle.
This title is what you are looking for to greet, but if you want to go deeper you can check if that account is linked with Google+ and use googleplususerid to retrieve more information via Google+ API.