Choosing a larger pool means that you will see more frequent (but smaller) payouts, but choosing a smaller pools helps keep the network decentralised. [Miners will not lose any revenue by mining on a smaller pool](https://redd.it/g6uh2l).
[Consider using Tor to connect to the pool](https://xmrig.com/docs/miner/tor) (or to a hidden service pool like HashVault, RespectXMR and MoneroOcean). This hides mining activity from your ISP, and prevents the pool from knowing who you are.
Find the line in config.json that says `algo: null` and change it to `algo: "rx/0"`. By default, XMRig expects the pool to tell it which hashing algorithm to use.
Most pools are <abbr title="Pay Per Last N Shares">PPLNS</abbr> pools, which means that you only get paid when a miner on the pool finds a block. If the pool you are mining on is small, this can take a few days to weeks.
On some CPUs, XMRig tries to increase performance by disabling certain features like your CPU's instruction prefetcher. These operations require root/administrator, so try right clicking xmrig.exe and running it as administrator, or running `sudo ./xmrig` on other systems.