Hello!
Welcome to Linode!
Networking is a common source of confusion so this is an excellent question. The short answer to your question is that your IP address will not change. Linode uses DHCP by default to acquire your IP address when the Linode is booted for the first time, but the IP address that it acquires is "assigned" to your Linode and will never change.
If you decide to use a private IP address or need multiple public IP addresses you would need to set up static networking[1] or use the Network Helper[2] to do it for you. If you are only planning on having the single IP address for your Linode then you do not have to do anything and your IP address will never change.
Best,
Lev
[1]
https://www.linode.com/docs/networking/ ... figuration[2]
https://www.linode.com/docs/platform/network-helper