To step in software testing company to build a career in the said field, you must follow a series of steps:
Get a proper degree in Computer Science, B Tech, MCA or BCA.
Get yourself accredited with a high-level certification such as ISTQB OR CSTB
Develop excellent communication skills
Develop analytical skills to better understand system units and how to create use cases
Focus on developing technical skills ( Linux, SQL, Databases)
Get hands-on practice of Testing Tools, Automation Tools, Testlink, Defect Tracking Tool to build expertise in all of them.