This requires you to use video editing software. There are many kinds. You can choose one you like. For example, editing, audio and video, EDIUS, adobe premiere and so on are all good software. I personally recommend you to use love editing. This operation is very simple, as you said, add some text special effects, which can be operated by any layman. The following one is very professional and is not recommended by most people. Just play a little video. It's overqualified.

The software is usually based on the timeline interface, and the recorded dynamic video clips are arranged on the timeline according to the playing order. Nonlinear editing software provides various tools for editing clips, including cutting, dividing and cutting, and can also rearrange clips on the time axis. With the development and progress of nonlinear editing software, its functions are gradually expanding. Most consumers and professional nonlinear editing systems have also added the functions of adjusting video color, video correction and visual effects, and can also edit or mix audio synchronized with video sequences.

When the editing project is completed, the nonlinear editing system can output the plan into various formats, including video format for public broadcasting or compressed file format that can be transmitted through the network, DVD and mobile devices.