|Yes, you may have up to 3 accounts. One Main account and two multiple accounts.|
They must never interact with one another in the game and there are many rules regarding what multiple accounts can or cannot do. You ought to read the rules; https://www.lordswm.com/help.php?section=5 numbered 3 - 3.13.7. which relate to having multiple accounts before deciding to create them.
There is also an old topic with multi account FAQs - https://www.lordswm.com/forum_messages.php?tid=1847758 - It is slightly outdated, so you are best to read the rules and ask any questions you may have in this topic.