Girona remind me of Newcastle in the Champions League, I think they might try their best to advance to knockout stage but I won't think much about them since some of their players are out already and they might not be able to replicate such form but maybe they might be fortunate to do better than Newcastle
There are worse options than what happened to Newcastle - for example Union Berlin. They failed in the Champions League and miraculously remained in the Bundesliga, were very close to relegation. But I think that despite the fact that Girona lost several players, such a failure is not threatening them. I think they will be able to qualify for the 1/8 finals of the Champions League (in the new format it is much easier for newcomers) and then everything will depend on the draw.
There are many new or surprise teams that will play in the Champions League next season, but of these teams, Girona actually tends to be stronger financially than Newcastle before, but even so, we can't expect much from surprise teams who don't have the mentality and experience in the Champions League, just like you, I also suspect that teams like Girona, Bologna, Atlanta, Brest and even Stuttgart and Leipzig will not be able to do much in the Champions League next season even though they are currently improving their squad, the quality of the squad that a teams has team does not guarantee that the team can easily compete in the champions league so far and we can see how every season PSG continues to improve the quality of their team but instead continues to fail in the champions league, because the existence of competitive competition in the champions league has always required a team must the mentality, performance and also high consistency to be able to do it.