No need to worry, Madrid is a very solid team and can always provide the best for new players so that they can feel at home and comfortable appearing with Madrid to get consistent performances in pursuing prestigious titles and I am sure Mbappe will adapt very quickly to other Madrid players.
It's okay to hope for Mbappe, but the most important thing is don't get your hopes up because the match hasn't started yet.
And for Joselu there is nothing that can be done before he is made permanent by Madrid because currently Joselu contract has expired but Madrid hopes to make him permanent because he has quality talent that is suitable to be Madrid reserve player.
Yes, I believe Real Madrid has been a pretty solid club so far and in fact the Real Madrid players are quite comfortable playing there even though Real Madrid has a lot of great players but they still work together to show their best, after all Carlo Ancelotti will definitely do his best for At the club, he is an experienced coach so he really understands how to set strategies for his players and doesn't just rely on Mbappe because Mbappe is a new player for Real Madrid so he needs a long adaptation and Ancelotti will definitely make the player adapt quickly so he can quickly contribute to the cause for club.
Talking about Juselu, I have heard that Real Madrid is willing to make this player permanent. Moreover, the price is not that expensive, so Real Madrid doesn't really mind, but regarding his position at Real Madrid, I'm not sure Carlo Anceloti will use him. I think he doesn't have much time to play and is only used only when he needs it, for example if Real Madrid's mainstay player is tired or injured, maybe he will fill the gap.