
I've taken the pertinent information from Carl's Sims Guides to use for this challenge. The guide has some good advice and information that will be beneficial to us all, for this career.
The Sims 4 Business Career
Management Branch
The Sims 4 Business Career features both Management and Investor Branches. (We will be following the Management Branch for this Challenge). Both of these may offer you opportunities that could, at random, make your Sim some extra money based on what you select and some random variation. The Career relies heavily on the Charisma and Logic Skills, no matter which branch you take. While it starts with an Ideal Mood of Energized, it shifts to Confident at Regional Manager (level 5) while the Career offers you to select a branch upon reaching level 7. At this point it is necessary that you choose to follow the Management Branch for this challenge. Since Emotional buffs are fairly easy to get, you don't need any special traits to pursue either of these Careers. However, Outgoing and a Popularity Aspiration (to give the Gregarious Bonus Trait) may be helpful to levelling Charisma and making Friends. While Friends are not necessary, it's just a perk to be able to have your social interactions succeed more often and perhaps level Charisma faster.
The starting Daily Task, Fill out Reports, can be found on the Computer under the Web menu. Filling out Reports may sometimes give your Sim a Bored Moodlet, "Paperwork Drudgery". This is tough, as it takes a few hours to do and you're already gone for the 9-5. Just accept that your Sim has less time in the early levels and will eventually get a better job without the boring paperwork.
Business Career
(Since the game actually tells you what is required for advancement to the next level - I've chosen not to include that information here.)
1 Mailroom Technician
2 Office Assistant
3 Assistant to the Manager
4 Assistant Manager
5 Regional Manager
6 Senior Manager
Management Career
The Management Career Branch features Confident Aura items, which are appropriate for the Career however not very useful for gaining progress in it because they don't work when you're out of the room. They may, however, help with the success rate of Make Business Calls (found on the Phone under Household), which may only be done from 8PM-8AM on Weekdays - meaning your Sim needs to do them after work hours. Making these calls can help you get promoted faster so long as you have the Skill requirements met. Sims who make successful calls may get a Confident or +2 Embarrassed Moodlet depending whether they succeed or fail at the deal. It's more important you complete them than if you bother to make them. I'd do them after work so that there is no chance of going into work totally embarrassed and risking some kind of freak accident emotional death. In order to get Confident before Work, you can simply Psych Self Up using a mirror or make your Sim brush their teeth.
Management Career Branch
7 Vice-President
8 President
9 CEO
10 Business Tycoon
So basically, the goal is to top out in the Business Career following the Management Career Branch and becoming a Business Tycoon.
Hoping if you choose to do this you will share your Business Adventures with us in a new post. Thank you!!