Iām afraid there is no exact answer to your question. Creating a game, especially a multiplayer one, especially an MMO format, involves a huge number of individual tasks that can already be answered (for example, on this forum).
If you are new to Unreal, then you need to learn a lot, starting from the very basics. Find and study lessons on creating a character, widgets, unreal network system, animation.
To create an MMO you will need all this knowledge.
In addition, the amount of work you will face when creating an MMO is too much for one person, you will need to find a team.