Teyana Taylor is gearing up for the Oscars, but she’s trying not to think too far ahead ... even though it could very well be her name that gets called for Best Supporting Actress Sunday night. We caught up with Teyana at L.A. hotspot Mr. Chow during a pre-Oscars party Thursday ... where she told us she’s nervously planning to write a speech -- "just in case" she wins for her role in "One Battle After Another." Catch the clip ... 'cause she also gives a hilarious impression of what it would