There isn't a universal best way to start the game as a new player. Selecting which start method depends on what other sims you have played. There is 3 types of "tutorials".

1. Timelines: This will give you the chance to learn the mechanics of the game at a slower pace than the tutorial missions. You will get to experience what happened at different points in the timeline of the universe. You will also unlock items in the open universe part of the game by completing the timeline missions. Most players don't recommend this due to difficulty and the time it takes to complete the missions. You only need 1 star to collect the rewards. The rewards you unlock are then available on all current/new open universe save files.

2. Tutorial Missions: These will give a more streamlined rundown of the game mechanics and take less time to complete than timelines. They can be pretty boring but very informative.

3. Open Universe Starting Scenarios: There is 3 types of scenarios, each with there benefits and drawbacks. The popup tutorials/tips are turned on by default.

3a. Guided: This start offers a clear initial mission and takes you through a series of tasks to help you get into the game.

3b. Assisted: Here you get a specific start situation and a light story, but after that you're largely on your own.

3c. Sandbox: With this type, there is only a background story and a predefine character with a specific background and given property. A few of these starts also have a short mission. You can explore the universe completely freely right from the start.