first doctor appointment advise please!

its up to you if you want to take them. I personally do all of them, I want to be as best prepared as I can

I never do them. A lot of these tests have high rate of false negatives, not to mention they make people super paranoid. 

I have always denied them. Too many false positives and them you are subject to more tests and then all you do is worry and stress til baby is born. And, more times than not, baby is 100% healthy...

I know a few people who had test and were told that their baby had down syndrome or something else...and they turned out fine! They do this early so the mothers can choose to abort if they wish based on the results. I personally will not do that test, because it could be wrong and I would want the baby either way.

there is very little in a pregnancy that you have to do. However, most of the tests are basic. Likein your first one they were also checking your hormones levels to make sure that they are rising like they are supposed to. The one test I wish we hadn't done and I won't do again, is the quad test between 15-20 weeks. It has a 60% false positive rate and when you get a false positive (like I did) the stress isn't worth it. I suggest not doing that test, but that is my opinion. 

Ive opted to do the tests twice now simply because I want to know in advance if something might be wrong. To me its no different than getting an ultrasound done when they do the anatomy and gender check making sure everything is growing ok and not seeing any abnormalities ie.. heart issues, bands on babys arms/legs, just anything unnatural. I dont stress about the tests until they tell me something is wrong