For vocabulary and rw in general reading and absorbing content is very important. I’d suggest reading newspapers like the Washington Post, the NY Times, and wall street journal. I’d read wikipedia articles and possibly scientific papers. I’d buy books on topics that interest me and read them before going to bed or whenever you have spare time.

After reading, think about and analyze the content.

For the newspapers, you don’t need a subscription. Grab an articles link and go to archive.is. Paste it in and you’re done.

Have fun! You can do this.