Advice on how to start from scratch?

Hey, as the title says I am looking to start my journey into becoming a data analyst. I am almost finished my degree in political science and realised I would love to be a data analyst. I have a few questions:

1) As a newbie, is online courses such as the 'Google Data Analytics Certificate' a worthy course to learn the basics?

2) Is it optimal to learn these main skills: Excel, SQL, Tableau and R / Python? (am I missing any?)

3) Once I feel proficient in each skills ^, should I commit to creating projects to show of my skills?

4) I have searched for helpful material such as this however are there any other helpful materials you would recommend to beginners?

I understand it will take time to learn all this and I am committed to doing so, I just want to be as efficient as possible in my learning. Any help is greatly appreciated! :)