The English language is an indispensable language for communication as well as for work today. Diplomas and certificates of language proficiency with a specific level (B2/C1) are a necessity in order to be able to apply to universities, internships, as well as for hiring. I was an English language trainer for 2 years, and I can reassure you that with a little discipline and work, it will be easy to learn all the basics to have these certificates. Regarding science, as I am an engineer. I can only reassure you that, if you were a science student, you will need these subjects throughout your career.