Hey,
If your focus is to get a job with BI tools, then I would suggest you go for long term purposes. Though every business has its own requirements. If you do not have any cost problem, then I would suggest you go for Tableau for your first choice.
Some of the properties are there regarding VISUALIZATION when it comes to visualization both tools have their strengths. Power BI can be handier if you want Data Manipulation and better visuals. If your prime focus is visualization then Tableau has an edge over Power BI.
To know more about the COST, LICENSING, VISUALIZATION, IMPLEMENTATION, DATA ANALYSIS and more can go through this: https://www.edureka.co/blog/power-bi-vs-tableau/