It's an iPhone 7.
1 It currently has iOS 12.4 but I have the update 13.1.3 available to update to.
A any ideas how long an update would take?
B any bugs with the newer iOS I should be aware of?
With last phone I'm afraid I rather neglected the iOS updates BECAUSE of reports in the news and comments from users online that there were big problems with certain iOS versions but this resulted in me not updating for ages and caused other problems, want to avoid that this time.
2 Because of the problems I was having with last phone I fairly recently did a backup to iCloud after not doing for ages.
A concern I have with this phone is it's half the memory of the old phone (se 64gb this one only has 32gb and according to info on settings I ALREADY have used 16gb mainly on apps pre loaded which I'll never bloody use 
) so I'm wary of downloading the iCloud backup to this phone and actually I'm not really sure I want to. The photos I didn't want to lose I emailed to myself (in case the iCloud backup hadn't worked) and the apps I use regularly I'm just downloading semi-fresh to this phone. There were likely a load of apps and "stuff" backed up to iCloud that I didn't really use, won't miss and don't want clogging up my memory.
So I would appreciate thoughts/comments on this.
3 now to fun side - any apps/games you would recommend? Tips for using iPhone 7?
Looking forward to reading replies.