Is there supposed to be space between aligner and teeth?

Unfortunately, this is a question that is pretty difficult to answer without seeing what you are describing.  I would ask for a picture, but I imagine that taking a photo would be extremely difficult to say the least.  With that said, the best advice that I can offer is giving it a few days, then returning to your dentist for an adjustment.  Things like this can usually be very easily adjusted while you're in the dental chair.  This is why the aligners are not just sent to you at your home, a dentist is the better one to monitor and adjust them.  In my 10 years of practicing, I have never had to send back a Clear Correct case or an Invisalign case because of this type of issue.  However, I have had to make adjustments to many aligners over the past 10 years.  I encourage you to seek the help of your dentist to remedy this problem. Good luck and if you have any additional questions, just follow me on Real Self.

Aligners are customized for your teeth, specifically, based on impressions taken by your dentist. You will notice a difference in every new set of aligners you wear as they gradually shift your smile toward achieving the outcome you and your dentist planned for.If you have concerns about any of the aligner sets, don't be afraid to contact your dentist.

Congratulations to you for starting your journey on a new SMILE!You are correct, clear braces are fabricated by taking initial impressions of your teeth which are then sent to a lab where they scan the impressions into a computer which then will fabricate your custom trays. Acquiring Impressions with putty or PVS material ~ In the process of taking those initial impressions with a putty or PVS material, there are times that you may have a distorted impression. Usually this is caught by the lab technician and your dentist may call you back in to remake an impression. Distortion can happen by the technique that was used by the dentist or assistant, or during the shipping process. Acquiring Impression with iTero (intraoral scanner) ~ In the process of taking your initial impressions with iTero, the dentist will use an intraoral scanner to acquire your impressions digitally. There is a lot of research produced that states the iTero is the best way to acquire impressions for accurate fit. However; PVS material is used today and when taken properly can produce an equally great product. Just another thought, as you are wearing your aligners, they should start out fitting tight and by days 5-7 you should fill a difference in how much easier it is to take them in or out. This is because the first days of each new aligner is moving the teeth and the last few days of the aligner are holding the teeth in the set position. If you feel like you continue to have a space between your teeth and the aligner, have your dentist check the fit of the tray. It maybe something he is able to fix at the office or perhaps he may have to acquire new impressions to have your trays remade. While you are at the dentist, ask them about whitening your smile using your Invisalign trays & a take home whitening gel. Our patients love this added bonus! 

If they fit perfectly tight, there would be no room for the teeth to move TO.  Ideally the aligners will fit better at the end of their use, normally 2 weeks later.