If you have a laptop you can prepare a presentation and then record your voice while running it.
You can do both with open office impress and with MS office powerpoint.
https://www.youtube.com/watch?v=LtL9tq0gbjk
https://support.office.com/en-us/article/record-a-slide-show-with-narration-and-slide-timings-0b9502c6-5f6c-40ae-b1e7-e47d8741161c