*NOOB ALERT* General Advice

Hi all, here’s a general query from a guy who’s tried, given up, and now is trying again to figure out Cubase!

My Hardware/Software:
In 2013 I got a Yamaha AudioGram 6, it came with Cubase 5 AI
I have an AudioTechnia condenser mic
I have all the necessary instruments/leads/computers/headphones

My Status:
I’m generally OK with IT stuff, but my goodness, the installation threw me, and the ‘popping’ ‘static’ etc. in my recordings meant i just forgot about it for years. Not anymore. I’m, after a full day, now back up any in business (popping doesn’t seem to be happening anymore, maybe something to do with the bit-rate/sampler driver settings I tweaked. Not sure. Not complaining)

My Purposes:
To record piano, acoustic guitar, and vocals at home. Either originals, or worship songs for church, etc.

My Questions:

  1. Given my above hardware and software, am I ‘good to go’? Or should I seriously consider upgrading, at least my Cubase 5 AI? What am i missing out on?
  2. Recording is one thing, but having the set-up, frequencies, etc. to make it sound good is another. Furthermore, editing, mixing, and mastering make a big difference. Any links available for tutorials on this in Cubase (5)?
  3. Here is a demo I did yesterday. https://www.dropbox.com/s/uyscuaqpsu986q3/test1.mp3?dl=0 Is that what i should be expecting given above gear, or can a lot of that be ‘cleaned up’ with editing/mixing/mastering? I don’t need to know how, just that i can get more from the setup.
  4. Everyone is talking about plugins… Is there an “Essentials” list for what you MUST HAVE if running Cubase AI 5, with my purposes stated above?

Thanks everyone. I greatly appreciate the support.
David