It's not easy because the champions league itself isn't all that friendly especially to new teams and I say this cause of the experience I have seen from most teams like Leipzig, Newcastle, and some others and all have failed to make any positive growth and that's why I don't feel any positive achievement will be made to their champions league campaign, but although am not sure for their Laliga journey but the champions league am sure that they will be knocked out.
Like other breakout teams, Girona might find it very hard to cope with the intensity of the Champions league. It's not the Spanish league where they were familiar with all the teams they went up against. All the elite teams play in the Champions league and Girona will have much more on their plates. It's not just girona, but teams that arw prolific in their domestic league don't usually do well in UCL. See the likes or Salzburg or Newcastle as you have mentioned. I'd like to think that teams like that mainly consider their UCL qualification as an achievement and anything after that — getting past group phase, knockout stages, eyc as a bonus. Not to mentioned thru have sold some of their best players.
If I'm not mistaken, this is the first time for Girona to feel the atmosphere in the Champions League. Obviously this is not something easy, because in the Champions League the opponents they will face are also not like the usual teams, there are many big and strong teams that they have to face. In addition, the Champions League also requires a very strong mentality, because it will be very influential when they face heavy pressure. Pressure also does not only come from within the field, but the pressure can also come from outside the field. However, this is a great achievement for them, Girona can prove that they can also be in the Champions League with a struggle that is not easy. I hope they don't miss this opportunity, they must be able to show that they can compete, yes, even though it is something difficult for a team that is not used to it like them.
Just like i said before that Girona consistency will be tested next season when they have to divide their focus to playing at several different competitions besides Laliga such as Champion League so we will see whether they still able to performing well just like they showed last season or not but because this is the first time for Girona so i think it's hard for them because Champion League has different atmosphere compared to Laliga
Because next season Champion League will have new format i think to qualified to knockout stages is more difficult for the participant teams including Girona because at league phase they will fight against plenty of strong teams early from different countries so that's why i personally didn't expect more to Girona performance in this competition even most likely Girona will not able to qualified to round of 16
Besides Girona i would like to see the performance of other teams such as Leverkusen, Bilbao and Atalanta because last season their performance is really surprised us especially Leverkusen that they had just make records 51 matches unbeated which i am sure those records cannot be surpassed by other teams in the near future so i am curious want to see Leverkusen journey in this competition and do not forget too about Atalanta i think thy are dark horses team who has the potential to trouble the big teams