It seems like you are trying to create multiple Instagram accounts. In order to do so, you may need to learn how to spoof device IDs and IMEI numbers. It is recommended that you create these accounts using the official Instagram app, as the quality of these accounts is superior to those created via the web.
If you find that your account gets suspended after a few days, it may be because Instagram has detected some sort of fingerprint that is leaking. This could be caused by various factors such as proxies, phone numbers, emails, device IDs, and others.