A new hosting account is an empty server with a control panel, and the number of things you could do first is why people stall. There are five that matter, they take about an hour together, and everything else can wait.
This assumes the account is provisioned and you have the welcome email. If not, activating your hosting service explains that first.
1. Log in and secure the account
cPanel is at your domain followed by /cpanel, or at the server hostname on port 2083. The second works before your domain points here, which is useful on day one.
Change the password to one you generated and stored in a password manager. This login opens every file, database and mailbox on the account, and it is attacked by automated attempts continuously.
Then set the contact address to a mailbox you actually read, and not one on this account. Quota warnings and important notices go there; if it lives on the site that has the problem, the warning goes with it.
2. Get the site onto the server, before DNS
You can build everything while the domain still points elsewhere. Nobody sees this work, and a mistake costs nothing.
For a new site, the one-click installer handles WordPress in about two minutes. There is more on the form, and the directory field is the one to get right in installing WordPress with one click.
For an existing site, request the free migration instead of doing it yourself. A proper cPanel transfer carries email, forwarders and cron jobs that a manual copy loses. Requesting a free migration goes into what to provide.
Everything you upload goes in public_html. Files above it are not served, which explains most of the confusion new users have with File Manager.
3. Test before you switch
Add a hosts file entry mapping the domain to the server's address. Your machine then loads the new server while everyone else keeps reaching the old one.
Walk through the site properly. A deep page, not just the homepage, plus a form and the admin area. Testing your website walks through what each failure means.
Expect a certificate warning at this stage. It is correct: no certificate exists for a domain that does not yet point here.
4. Point the domain here
Change the nameservers at your registrar to the two in your welcome email. This is the one step you cannot quietly undo, which is why it comes after testing.
Propagation takes up to 24 to 48 hours, during which some visitors reach the old server and some the new one. That is expected and cannot be forced, changing nameservers walks through recording your existing DNS records first, because a nameserver change hands the whole zone to a new provider that starts from defaults.
Then remove the hosts file entry, or you will keep seeing the new server and be unable to tell whether the switch worked.
5. SSL and backups, once DNS resolves
Both of these can only happen now.
SSL. Check the SSL/TLS Status page in cPanel and run AutoSSL for anything not covered. Then set the site to use HTTPS everywhere. A valid certificate on a site still serving HTTP protects very little. Forcing HTTPS walks through the redirect.
Backups. Whatever your old host was doing does not follow you. Set up something automatic that stores a copy off the server, and test a restore once. An untested backup is a hypothesis. Creating and restoring backups goes into both.
Then email, if you use it here
Create mailboxes only for people who will actually log in; use forwarders for info@ and similar, which store nothing and have no password to compromise. Creating email accounts walks through the distinction.
Then publish SPF, DKIM and DMARC. Without them, major providers treat your mail as suspect regardless of what it says. Understanding SPF, DKIM and DMARC goes into doing it in the right order.
What can wait
Performance tuning, before you have traffic to measure. Extra subdomains you have not planned. Anything the checkout offered that you have not needed yet.
The five above give you a working, secured, backed-up site. Everything else is easier to decide once something is actually running.
If any of the terms above were unfamiliar, Introduction to Web Hosting at Ahosting explains what hosting actually provides and how the pieces fit together.
If any of the vocabulary here was unfamiliar, Hosting Terms Explained: A Plain Glossary defines the terms in one place.
Once it is running, a short schedule keeps it running. A Yearly Website Maintenance Checklist deals with what to check monthly, quarterly and annually.
Know where to look when something is wrong
Three places answer most questions about an account before any ticket is needed. The error log names what failed and when. The resource figures say whether a limit was reached. And the disk usage says whether anything can be written at all. Reading those three takes two minutes and turns a vague report into a specific one, which is the difference between a support exchange that resolves today and one that takes a week of questions.