As practice, try telling a story with your b-roll and planning out a shot sequence. For example, your subject might open a door from the hallway, walk into their office space, sit down at their desk, open their laptop, and begin typing. Seems simple, right? But a shot sequence showing this 10-second scenario might consist of six or more different b-roll clips.
Tripods range tremendously in price, and the quality of your tripod should depend on the level of camera and lens you have. If you're shooting with your phone, you can get by with a table mount like the Arkon Tripod Mount or a full-size tripod like the Acuvar 50” Aluminum Tripod. For a DSLR, Manfrotto makes a variety of trustworthy tripods starting with the Manfrotto BeFree and increasing in quality and price from there.
When it comes time to shoot, clear out unnecessary people from the room and turn off the overhead lights. With your three-point lighting setup, there will be no need for those harsh fluorescents. When — and only when — everything is set up, call in your talent. There's nothing worse than being nervous, and then having to anxiously watch as lights are turned on and the camera is tested.