project design, am I understanding this correctly

I'm a software developer but always worked on "small" projects/solutions. Now I'm trying to create an application from scratch on my own, just to stay in touch with new developments and learn new stuff. I'm trying to use everything I've never used before.
So basically that means I'm developing a c# application, using EF core 2.1 and SQL Server.
I've read a lot of articles online and I learned A LOT already. But I'm still confused because everyday I find a new article using a different approach. I would like the opinion of some other developers on what I've got so far.

First of all I'm used to WinForms so for now I'll use that as my UI. Just because I can get fast results with it. Afterwards I'll try using ASP.NET Core. I also want to be able to use an other UI and still be able to use the rest of my solution.
I have several projects in my solution:
1. Data: EF Context, DbSets, Migrations
2. Models: EF models, used in EF Context (nothing more then POCO's)
3. DTO: Objects exposed to the UI (again, classes and properties, nothing more)
4. Mapper: "DTO to Model" and "Model to DTO"
5. Services: static classes and static methods/functions using all the above, containing the logic. for example GetCustomer uses the EF context class to read the database, gets the model, maps it to a DTO and returns it.
6. UI: binds to the DTO objects and uses the services for every user "action".

That's it, in a nutshell. But am I on the right track?
I've read a lot about IoC but I'm not there yet, but as far as I understand that has "nothing" to do with the above.
I do have 1 specific question: In WinForms there is validation using the IDataErrorInfo interface and for binding I need the INotifyPropertyChanged logic. Where does this belong? I would say in my DTOs but some say a DTO "can't have" any logic.

I'm sorry for the long "question" but I'll appreciate any input to make sure I understand all of this correctly.