Golf club questions

I am a novice golfer and I have some basic equipment questions.

1.  I purchased a set of Nike clubs about a year ago.  At what point do I get fitted?  I figured there was no point in getting fitted until you have a good solid swing.

2.  Are you faithful to a particular manufacturer or do you "mix and match" your clubs?

3.  How many years do you use a club before you retire it in favor of a new one?

4.  I don't buy the expensive balls yet because I'm still losing a half dozen after 18 holes.  For those who have and advanced golf skill, do you buy the expensive balls or are you ok with your basic Slazenger?

I wouldn't worry about getting fitted until you have a fairly repeatable swing. I'd wait until I was shooting in the mid-90's before getting a fitting. You may want to have your irons lie angle checked as this can throw things off a bit. You can do it yourself - take some electrical tape and place on the sole of an iron. Hit 5 balls of a matt. The scuff marks should be in the center. If they are all towards the toe or the heel (a 1/4" from center or more) you should have it adjusted. Do this for all irons.

NO. Feel free to mix and match. I have 6 different brands in my bag at the moment.

Until they don't fit my needs anymore. Generally I look at drivers every 2-3 years because of technology changes. Current model is 2 years old. Otherwise I play the same clubs unless they wear out or something changes.

All depends on your game. I shoot low 80's consistently and play mid-low priced balls. There are some great options out there for $20-25 a dozen. I also find a lot of pro-v1 and play those but don't seem to score any better than with the mid price balls. Play a ball that fits your game