Yes, I think it is very likely that there will be many goals scored in this match and for the over 2.5 bet option, I think it is quite worth choosing
And as for the chances of winning, I think Chelsea have a pretty big chance, their first win last week, of course, makes this team even more motivated and have high confidence, while Nottingham have not performed well at the start of this season, they have suffered 2 defeats from 3 matches. and also if you look at the quality of these two teams, of course Chelsea are far superior and most likely they will be able to win the match.
Chelsea team is stronger and better than that of Nottingham Forest and I expect them to win the match, they even added a very good player Palmer Cole from Manchester City and that's going to be a boost to their club I don't know if Pouchettino would start him against Nottingham Forest but if he does you could imagine a midfield trio of Caicedo, Enzo and Palmer, all young and talented and I don't think Nottingham Forest midfielders could compete with them on the pitch, Chelsea would be playing at Stamford Bridge which gives them a very big advantage so i expect them to win the match comfortably like you said and a 2.5 goal margin or more might likely be the outcome of the match, in favour of the home team, Nottingham Forest in return lost one of their key players Brennan Johnson to Tottenham and it might affect them in the match against Chelsea.