Teaching for the first time: is reaching out to each student acceptable? I work as a programmer as a full time job. Since I'm an experienced programmer and have some teaching aptitude, I've been asked to give a 40-hour course in C# programming to a computer science group of 70 students.

I've given two lessons so far (4 hours total), mixing lecture and practice sessions. I think I'm doing just fine but I'd like to reduce the number of students I'll lose along the way.
I thought I would make each student more engaged if I established a conversation with them, even if that might prove to be time consuming. I already have an ongoing conversation with (roughly) a fourth of them, since they reached out to me to ask questions and be advised on practical matters. Plus, they did the excercises I assigned to them.

How should I act with the rest of the students? Today I thought I would be sending a message to each of them (we're in a Slack team) just to check if they've understood the lessons and be helpful in giving advice in case they were stumped by simple matters they might be too shy/afraid to report.
On the other hand, I understand they are adults and that I should not babysit them. What would you do?

Thank you in advance.
Establishing cordial relations with students is almost always beneficial in education. By making connections with them you are providing a form OF social support that helps with retention and academic performance.
Your concern with babysitting relates more to.the students expertise in the subject matter rather than their age. Novice students normally require much more support than advanced students regardless of their age.