The first thing to learn once you know how the pieces move is basic tactics and general strategy.
Tactics: In certain positions it is possible to gain an advantage doing a certain move or sequence of moves. This is referred to as tactical motif/pattern and for a list of all kinds of motifs take a look here. You don't need to start learning all of them at once, but eventually you will. The idea is that you recognize the pattern (not a particular position) that enable these tactics and burn the pattern into your brain so that you immediately recognize it when playing chess. As a beginner I'd start with the following motifs:
- hanging piece (make sure that you always check which of your pieces are attacked and which of the opponent's pieces you attack) and related to this the motif of counting (if there is a sequence of captures); knowing about the value of pieces is essential here
- simple mating patterns (back rank mate, Scholar's mate and similar mates,..., king and queen vs. lone king, etc)
- double attack; particularly pawn and knight forks
You can practice your tactics by solving puzzles on many websites like chesstempo, lichess, chess.com... Usually (if it is a good website) the problem you are given to solve is adapted to your level.
Strategy: This refers to general rules on how you should play in order to gain an advantage in the long term. Most important for a beginner I'd consider the following opening principles:
- develop pieces (knight, bishop) quickly in the opening; don't move a piece twice unless forced to do so
- occupy the center (typically you rather want to move the central pawns (on c-d-e-f files) two steps (or more) than the outside pawns (a-b, g-h files).
- put pieces on meaningful squares, usually so that they attack something or cover many squares
- king safety (usually this means castling and hiding behind your own pawns)
Your move 1. Nh3 does not do anything to occupy the center (1. Nf3 would be more suited for that) and also knights on the border of the chess board are somewhat limited (as they say: "a night on the rim is dim").
As with tactics, there are also positional/strategic motifs. However these are a bit more difficult to understand than tactics. The best way to appreciate them IMO is to read/listen/watch commentated games of masters or even better to have your own games analyzed.
You should still keep on playing games, but avoid blitz or other short timed games. And analyzing your games afterwards to see where you went wrong (or where you made a great move) is also a good way to improve. On lichess (and perhaps other websites) you have a very useful feature that let's you have your games analyzed by a computer which will point out inaccuracies/mistakes/blunders.
And yes, if you can join a chess club that would be more efficient and fun than trying to learn everything on your own.