Bigger missions require sacrifices.

Select New Game from the menu, you find a player (yourself and some other people (players) that still don't know. The basic rule of the game is you have to assign the missions to yourself according to the way that you will choose and therefore you will choose your profession and role in the game. There are many ways, you have many rides, and equipments but again it depends on the role. So you might approach a car and try to drive it and it won't work. Don't waste the time. Try to walk or use a bus nearby… there are always alternatives.
The destination is also determined by you. If you find yourself in the wrong place, just move it and don't stand still.
There were many players who just lost because they got confused and didn't take any decision till the end of the game, the game has certain duration.
Some other players were impressed with all the buildings, cars, yachts and wanted them all. And they couldn't concentrate on their way, as their eyes were focused on what they want not how to achieve it.
The other players and who are abided by the same rules ... fair enough !

I didn't know what to choose, my strategy was to spend sometime watching other players and what their options have lead them to, then decide which way I will take.
Before I reach a conclusion, I started to give myself big missions, tried to find a way to achieve them, but I couldn't. I went and sit aside again thinking, my amended strategy was based on the fact that I lack the experience and the game is hard for me so let's begin with easy small tasks that will enable me to take bigger ones and at the same time to acquire the experience. That plan really worked but I have was trapped. by the time achieving small missions became of no importance to me and I don't expect them to increase my score. Moreover, I became old for this phase, I can no longer see the people who were in the same phase they went farther and new ones began to join. so it's enough for me. I mistakenly thought that being in the same phase and do more missions will give me the enough score that enables me to go to the second level. But I am really bored and may be it's not going to work this way. The only way out is to try new ways within this level and take risks .. I tried what I liked so why don't I try what I didn't like… . I can't have it ALL.
Bigger missions require time, effort, and something that you like the most to be given up. That's the key rule.