Real Madrid performed poorly in La Liga last season but played well in the Champions League, losing to the reigning champions in the semi-finals. So it may happen that this season they may do well in La Liga but poorly in the Champions League. We have to wait for the group stage and see how they perform.
This is still just speculation or personal opinion. I've seen how Real Madrid have played in the three games that have been played in La Liga, they played quite well and managed to get three consecutive wins even though they haven't found the right person to replace Benzema. Real Madrid's best purchase this season Bellingham has played extraordinary, he has scored four goals in three La Liga games. His arrival to Real Madrid has given new hope to the Bernabeu public after they just lost their Legend who had gone to the Arab League.
Real Madrid will focus on the Champions League and also La Liga, Ancelotti is trying to give something of value to Real Madrid as the most beautiful farewell gift at the end of the season.
Joselu, who was expected to replace Benzema, hasn't lived up to expectations, and Rodrygo, who is usually plotted in Benzema's position, hasn't shown his ability. Jude b is now a figure who is showing an extraordinary game. Although he is still relatively new to the team, he can show good adaptation and even he has always been a differentiator in the matches that Rael Madrid has played, so you could say he is Real Madrid's most successful transfer this season. Vini jr was not seen in the early matches but is now slowly improving his performance. But it is undeniable that Ancelotti still has a lot of work to do.
The champions league will be more difficult, especially now that they have a very strong competitor, it is Manchester City who are in rapid improvement.