We know its difficult to teach in front of camera first time.. But you can learn it quickly. After all background work like course structure, script etc its time to shoot your videos.
Step 1: Select Room
Select a quite place in your home to record your lectures. If possible select a dedicated space which is far from road / noisy places. Turn off noise making equipment like vents or fans, television, phone, washing machine etc. Keep the room as quite as possible. Please try selecting bigger space (avoid cramped space). Remove the clutter and avoid too many people in the recording space.
Step 2: Prepare background
Now select nice background for your video shooting. Make it natural. you can select just any plain wall also but some times they reflect too much light. You can use the seamless paper for background (try google it, you can find them for very reasonable price).
Step 3: Check lighting
Use natural light as much possible. Make sure there is plenty of light. At the same time avoid any light which is reflecting and distracting. Overhead lighting tend to create shadow on the face. You can use simple studio lights to adjust the amount of light required.
Step 4: Check audio
Make your recording space sound proof as much as possible. Generally empty rooms echo the sound and it will be too distracting. Also some objects the room can reverb the sound and make echo. Sound dampening sheets will do the magic, but you can use pillows to cover those echo making objects.
Before shooting your lectures, check your video and audio equipment are on desired settings and all the cables are connected. Relax and loosen up. Create test video and watch yourself for improvements before your shoot full length lectures. You can check more information here.