The most important part of becoming an expat is having enough money for your stay in the country that you plan to live in. You do NOT want to be homeless and at the mercy of others.
To ensure that you have enough money, you should get your finances in order well in advance. If you plan to work in the country, you need to ensure that you have the proper visas so that you don’t get in trouble with the law. 
To plan for life in the country that you plan to live in, create a budget sheet that outlines your planned expenses for your stay based on the cost of living in the area. Add a few hundred more dollars to the budget for unplanned expenses.
This leads to the second most important part - planning. 

  • How long does it take to get a visa? Can you work with that visa? Do you have to apply for an extra visa to be able to work?

  • How will you get your mail from your home country?

  • Where will you stay? Will you rent an apartment or house? What neighborhood do you want to live in? Will you live with roommates?

  • How will you get around? Will you rent or buy a car or a scooter? Is it possible to walk everywhere?

  • What activities will you participate in? Are there free activities? 

All of this needs to be taken into account when planning for your move.
The third part is to learn about the culture. You do not want to have cultural faux pas! Learn a few words in the native language and learn how they greet each other. The locals are sure to treat you with more respect if you take a little time to learn about their culture.
The final most important part is - having fun! Enjoy yourself. Things WON'T go as planned, and that's okay!