First, don't expect to get from 800 to 1000 in a week, it doesn't work that way. Keep playing, try doing more puzzles on Lichess and Chess.com, I would also recommend IM Silman's "Reasses your chess" as an excellent beginner to intermediate book.
How to stop a plateau at 800 elo

Congratulations on reaching 800 ELO! I wouldn't say you have 'plateaued', you are just like a baby who has just achieved sentience. You went from being able to calculate 0 moves ahead to 1-2 moves ahead approx. which is between a 100% to an infinite improvement on your chess ability.
Your rate of improvement will still overall be faster than the rest of the chess community, right now it just feels like you have plateau, learning how to calculate becomes exponentially harder with each move, and then you throw in tactics and positional concepts etc.
I would say you do not need the entire Silman book until you are at least 1000 ELO for a few months and you hit another plateau (Silman himself says 1400 USCF, but that seems a bit elitist). For now, you will still see RAPID improvement just spamming puzzles and gradually improving your pattern recognition and calculation.

I got to 800 elo and have not improved over the past week. What should I do to get to 1000 elo. I have good understanding of opening and tactics, but how can I take my chess game to another level?
id suggest you to check this blog https://www.chess.com/blog/hkchessking/how-do-we-improve-at-chess-for-people-who-are-stuck-in-their-rating

Try playing more . I started last year and I didn't read any books or do puzzles all that much and improved a lot. However if this does not work for you try doing puzzles and reading those books high ranked players suggest.
I got to 800 elo and have not improved over the past week. What should I do to get to 1000 elo. I have good understanding of opening and tactics, but how can I take my chess game to another level?