Project exporting goes very slow
Time of encoding mostly depends on the capacity of your hardware, but there are few ways to increase exporting speed.
If you're using Intel processor that supports QuickSync technology, you can install the latest version of Intel HD Graphics driver and then enable Intel hardware acceleration in Settings -> Preferences -> Acceleration menu of Video Editor.
If you're using NVIDIA videocard that supports NVENC technology, you can install the latest version of NVIDIA graphic driver and then enable NVIDIA hardware acceleration in Settings -> Preferences -> Acceleration menu of Video Editor.
Also, to reduce time of encoding you can select output format with the resolution that matches resolution of original video(s). For example, if you're using FullHD (1920x1080) videos from camera in the project, it would be better to select preset with the same resolution - select format HD video and then select preset with 1080p resolution to save video.
If you're a laptop user, you can also read this article.