Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
It's good of you to honestly confess that you are somewhat new to camera use on a professional level. It makes it easier to advise you usefully.
I doubt that your lenses are either of them in a state of malfunction. I think you need to consider settings.
First, you must consider, with regard to focus, what your 'speed' setting, or ISO speed, is. When set to a speed in the wrong direction, either fast or slow, photos will tend to be more blurry.
Second, is the lack of focus blurriness or 'smeared'-looking? or is it simply that the edge of everything is soft and fuzzy? the first type of lack of focus comes from wrong ISO speed, but the second comes from actual not-rightly-focused status in the lens.
If your are shooting pictures in Manual mode, this means you must adjust the ISO speed, and also manually set the focus to sharpness, before shooting the picture. Only in some camera modes, does the camera focus the picture for you - and even then, if there are foreground objects in the field of view and a more distant background, the focus may not be where you want it to be.
So check your ISO speed setting, check whether you are in Manual mode (as opposed to Auto mode, which auto-focuses), and if in Manual, be sure to focus properly by hand before shooting.
What should be my ISO speed be when recording? Also which one of the lens's i listed above do you think is best for recording?
The counter-question is, when you are recording what? fast-moving subject against distant background (like a bird in flight) ? fast-moving subject against nearer background (sports photography) ? dim light indoors? bright sunlight outdoors? something else?
ISO speed should be set according to some idea of what the lighting, and movement, conditions are, in the subject you will photograph. Still subject in dim light can use an speed, but the dim lighting will make a speed at one end of the range more efficient. Fast subjects require a fast ISO speed in order to avoid blurring, but require brighter lighting to come out properly.
These two pages go into the basics of using the ISO setting:
As for which lens... actually you list 3 lenses:
-AF-S DX NIKKOR 18-55MM F/3.5-5.6G VR II Lens-AF-S DX VR ZOOM-NIKKOR 55-200MM F/4-5.6G Lens-Tamron SP AF 17-50mm F/2.8
the first is a medium focal length lens.
the second is a long-focal-length lens, a Zoom lens basically.
the third is a medium-short focal-length lens.
The second one being a Zoom lens with highly variable and possibly long focal length, means it's made for outdoor photos of things at a distance. It might be best for outdoor and distant vistas or landscape photos, and also birds on boughs at a fair or long distance.
The other two are similar to each other, I think. But the Nikkor differs in having a variable F-setting value, but the Tamron has apparently a fixed or invariant F-setting value. That would make the Tamron rather specialized.