Orderbook in binance

[Lucacrebbe]

When I day-trade  I am  used  to  take  a look at the  order book  to find support  and resistance levels, yesterday for example  there were  in the book two big levels  for  USDtheter/BTC

One level in ask  was at price (i don't remember now)  with 20'000  conctracts.

The other level  was at bid price   with 35'000 contracts.

Can you explain me  please  how one  shoulf behave in this case?  Which  one is  the support and  which one  is  the resistence? The ask level or bid level?