Speak loudly, always look at your audience( unless if you need to look back at your paper) and if you are nervous, just picture everyone in their underwear.
A claim is the main argument. Evidence is the facts or research to support your claim. I hope you win your next argument! :D
You didn't italize or mark the phrase, but I see one good candidate:
"The circus animal trainer" is in a way another name given to Mervin, a kind of "renaming" him: this is called an appositive phrase, so if this was the phrase appositive phrase is the answer! (also, I don't see the other phrases here).