If I have a Pokemon with the "Top Entry" Ability in my starting hand at the beginning of the game, can I put it onto my Bench?
No, you may not. In order to use Top Entry it has to be drawn from your deck at the beginning of your turn, but your turn has not started while you're setting up at the beginning of the game.
Source: Rebel Clash FAQ (2020-04-18), TPCi Rules Team (2020-04-30)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH2_32
SWSH2_32