What is the best setup for a home recording studio?

I plan on doing some recording in the future and I would like some advice on the different aspects of doing home recordings.

What is the best environment? (Size of room, composition of walls, echo/reverb, etc.)

What is the best equipment? (Microphones, computer recording station, software) I’ll be recording vocals, acoustic guitar, piano and various electric instruments.

I’ve been using Adobe Audition which works great but I’m curious as to what the alternatives are and what are their pros and cons.

For the basics on setting up a home recording studio, check out this article: https://www.articlecube.com/Article/How-To-Build-A-Home-Recording-Studio/49379
Once you’ve read this, you’ll have a nice foundation. Audition is a nice program and can achieve professional results like many other multitrack recording software programs out there. However, I recommend getting a copy of Pro Tools as your main recording software for a few reasons. First, it is the industry standard in recording. Many major label records have been recorded on Pro Tools. Second, it’s easy to use and there’s plenty of support an tutorials available on the market to get you up an running in no time (see: https://cgi.ebay.com/Brainwerks-PRO-TOOLS-7-LE-M-Powered-HD-Tutorial-Video_W0QQitemZ260085583899QQihZ016QQcategoryZ41786QQtcZphotoQQcmdZViewItem ) Third, it’s easily portable to other studios that have Pro Tools (and many studios do!). This gives you the ability to record a session at home with your guitar and piano; save that session to disk; go to another studio with a nice drum and vocal room (if you choose) and pull the same session up on Pro Tools and add those elements. Then, you can take that session home to arrange and mix your project. Or you could send your Pro Tools session to professional mix engineer, to have it mixed. The sky’s the limit. The problem with other programs like Audition is that not as many studios use it (even though it’s a good program) so being able to transfer Audition sessions from studio to studio many not be as easy, because that studio will need to have Audition installed on their system (which many studios don’t). Another great point to add is that you can now get Pro Tools for around $250, making it very affordable for anyone who wants to put together a home studio. https://www.homerecorder.com/products/software/recording/protoolsmpowered.html
Hope this helps. Good luck!