Saira Elizabetti ,it is not too hard, but I did have to go to google for help here and there since Medium is not the most self-explanatory platform. You start by clicking your profile icon at the top of the Medium homepage. This will open a drop-down menu (the same one that has your profile, drafts, stats, etc on it). Select “publications”. This will pull up all the publications you follow, but in the upper right hand corner there is a large button that says “create publication”. From there it will (mostly) tell you what to do, although like I said, I had to google a few things. You can add stories to your publication by opening the story, going to the bottom and clicking on the ellipses symbol (…) on the bottom right hand. A drop-down menu will give you the option to add the story to a publication.
If you do decide to start one, feel free to hit me up if you have any questions once you get into the process! You can e-mail me at firstname.lastname@example.org. I’m certainly no techie but I did manage to fumble my way through it.