There should be no problem in principle with a single person having multiple user accounts.
The comment discussion in one of the answers to the feature request Signing in should sign you in on all sites on Codidact Meta very strongly suggests that even the Codidact administrators consider multiple accounts for one person to be acceptable:
You'd always be able to log out and log back in as a different account, even if the cookie is cross-network. I thought you could on SE as well, but it's been a while since I tried. — ArtOfCode 5 months ago
However, you should take care to not use multiple accounts to do things that you couldn't do with a single account. For example, you need to be careful to not use one of your accounts to vote for content posted using the other account, or give the impression of greater community support than is warranted.
Also, the third bullet point in section 1 of the terms of service would apply.
- If you sign up for an account and it is terminated due to your misconduct or contravention of these Terms, you may no longer use the Service.
This implies that if any of your accounts is terminated due to misconduct or contravention of the TOS, the termination effectively applies to your using any account that you have access to. The prohibition is against you using the service (Codidact), not the account being used to use the service.
You will, of course, need to use different e-mail addresses to sign up for each account, since the account is identified by the associated e-mail address.