Newcastle are out of all European football.
We will play one of the winners of the Play Off Round (can't play another Group Winner (seeded team) until the Quarter Final).
So in the L16 draw, we will face one of:
Galatasaray
Lens
Braga
Benfica
Feyenoord
Milan
Young Boys
Shakhtar Donetsk
SC...
Round of 16: 23 February 2024
It's all here: https://www.uefa.com/uefaeuropaleague/news/027a-1641dbb4e215-91bce93221b1-1000--2023-24-uefa-europa-league-matches-final-key-dates/
Play off round draw Monday - we are not in it
Winners of Play off round enter the last 16 draw as unseeded teams (we are seeded) and that draw is not until after their games in February.
So you can put the credit cards away for two months.