Tools of the Trade
I now use VS Code for all my web development; because it's free and the same software that most expert web developers and agencies use. Previously I was an Espresso user, and before that I used TextWrangler for about a decade.
The advantage of VS Code is that it runs on a variety of computer operating systems. As an example, much of this website was coded on a 2009 MacBook Pro running Mint Linux. VS Code has arguably the best choice of extensions anywhere. Extensions like Project Manager, ESLint, Quokka, TODO Highlight, Live Server and Prettier are an absolute game changer for the serious web developer.
You might be like me and spend a number of hours a day (and night) busy coding in VS Code. Some days it will feel like your second home! Therefore it's well worth surrounding yourself with your favourite extensions and installing an attractive theme for some extra eye-candy. Right now, I am using the Cobalt2 theme by Wes Bos.
VS Code has a learning curve itself. If you've not used it before, I'd recommend you watch this excellent YouTube video hosted by freeCodeCamp.
An FTP client is also a must-have. These range in price from free to quite expensive. This is how you will transfer edited files from your computer, to a web hosting server. Some of the most popular FTP clients around right now include:
Using FTP is much easier than a file manager in your web browser. Another alternative (not documented here) is to use version tracking like GitHub, to commit your website changes into the cloud, and then configure GitHub to automatically sync those changes back to your website almost instantaneously.
For practicing web development and testing websites offline, a server environment like MAMP or XAMPP is worth installing. Both are free to download (for the basic versions). Create one or more folders inside 'htdocs' and with the server running, you can preview your websites over localhost, including PHP pages. A video here on YouTube walks you through MAMP setup.