Setting Objectives and Providing Feedbacks

As a new teacher to the classroom, I would like to know how I can encourage my students to do well, provide objectives that the students are able to meet and provide the necessary feedback to my students that would be helpful. When I was doing my undergrad, one of my education professor always reminds us to keep our objectives simple, only focus on one during a lesson and provide feedback that is tangible, positive for the students and also encouraging. However, being in the classroom, and teaching a different topic or levels in the same class, I struggle to do that. I am interested to know if there is anyone out there that can assist with information that would be helpful.