Hi!
A few hints:
If you find that it is too dead, put in a tall bookcase on the wall behind you and fill it with good books of different sizes, inserted so that they touch the back wall and the spines are at the naturally resulting distance from the back wall. That will be a diffuser and a great distraction from those long sessions.
Be ready to switch off the air handler during takes to keep the noise down.
Start with whatever DAW software you are comfortable with and move up if you wish after you start getting a good sound. That way you only have to learn one thing at a time.
Make it comfortable, please. I sit in a $200k studio as I type this. What most pro studios struggle to create is
hominess. Surround yourself with things that make you smile and feel comfortable. You can't beat the pros at the money game but you can make them wish they were in your home.
Bob