Eddie Howe got 2 great opponents in the EPL opener. Man City and Liverpool, but Brighton's last game they also lost 1-3. I think since Newcastle are owned by PIF from Saudi Arabia they will be stronger. The reason is because they have a lot of abundant funds to buy new players. But I was wrong, they didn't buy many big players for this season. So if performance drops it's not surprising. But for UCL I agree with you, Howe hasn't had much experience in Europe.
I think this is just the initial stage where PIF acquires ownership of Newcastle, Sandro Tonali is one of the best purchases I think. The price is also very expensive, AC Milan can build a new squad by releasing one player namely Tonali. It is true that Eddie Howe has no experience at all in the UCL, because throughout his career he has only coached Bournemouth and Burnley. We know that the two clubs have never entered the Champions League zone in the EPL in the last decade.
Joining Group F puts Newcastle in a difficult position, because after all Milan, PSG and Dortmound are the favourites. Newcastle could have qualified for the last 16 with any luck, if the other three clubs suffer a dip in form.