Depends on the team really. Some teams need a lot of signings so I'll be out scouring for players getting the scouts out and such like. Then I've got to sort out my tactics at the same time. Other teams already have players ready for the crude tactics I've made in the past and have good players for the league so not many improvements needed there.
as minisav said it depends, id imagine that if you start with Chelsea for example you dont need to do alot of work in the transfer market as there are not many unknown players to go for, so ill post what i can about my Farnborough save
1) Game Day 1 - was at 6 hours before i continued, mainly scouting and releasing dead wood, but also looking for coaches and training schedules, it took so long as my budget was 0 and only 200 pounds a week left for wages so i had to make sure i scouted all that i could to get a good idea on wages too as i didnt have alot to play with.
2) Game Day 5 - no idea
3) Your first competitive game - about 10 mins, after all the tinkering in friendlies i had my side pretty set and had a few signings in by then too so wasnt too hard
Day 1, I take a look at my Staff and I fire the deadwood so I can bring real skill to the club. I then work the training schedule and my tactical approach to the current season. I sort out the finances. I do my first interview. I also cancel all the "noname" friendlies ( usually 3 out of 5 matches ). I then replace those friendlies with Reserve team friendlies. It's a way to test all my players at the same time and see how my Assman is thinking. It takes me around 2 hours to get all set up. I don't do the scouting myself, instead I prefer to add a bit of realism, I ask my scouts to bring potential signings to me and then I look at them. Altho' I do scout the players on the rumors list myself.
Day 5, First reserve team friendly probably just ended. I start looking for potential players for those players who performed less than well. I also check what position the player played in the friendly, what is their actual position, what tactic they had put up with, what stats he needs for that kind of tactic and what tactic would he be good at.
First Competitive Game Day - Around 5 new players. Usually 1 Striker, 2 midfielders and 2 defenders. Also 3-month loanees. A loaned striker usually does wonders. ;) Usually a reserve loaned GK as well.
Well.. that's just a bit of what I do in my first days as manager in-charge at a club. In all honesty there's just so much I could talk about..
probably around an hour before the first day, then every other day fluctuates due to any one of million different reasons, sometimes it's seconds, others, hours. New regen days are my weakspot though, they can be a good 3 or 4 hours at least