Of course you can change your laptop, Fiverr doesn’t expect people to own magical laptops that will never die.
If it’s a new laptop, there shouldn’t be an issue at all. The only reason there might be an issue would be in the improbable case that it’s a used laptop that someone else used for their Fiverr account who also had the same IP as you.
You can use as many devices as you want to, even two or five laptops or other devices at once, the only thing you are not permitted to do is to operate more than one account.
Have fun with your new laptop and welcome on the forum.