I have created a custom user role to allow logged users to submit content into a specific section in the site. The problem is that I don't want the users enter into the dashboard (even when the role restricts any other function in the admin menu because the site is used for people old than 50 years and they get confused because they cannot see the frontend menu when they are in the backend). So is it possible to add an access to upload a "New content item" from the frontend?
You could use Dynamic Forms or create your own module that fully abstracts all the functionality you need.
The new dynamic forms in conjunction with workflows could be very useful here. i would just create my own module so rather than do it all over the Admin UI or a mixture or both.