Before using your dildo for the first time, wash it with water and neutral soap. You can also use a special soap designed for sex toys. Use a lot of lubrication, especially if you are going to penetrate anally. The vagina naturally lubricates itself, but the anus does not. So, put the lubricant all over the toy before penetration.
Using a dildo is a very simple process to do alone or with a partner. You control the insertion, force, speed, and movements of the dildo. It is all about experimenting and figuring out how to create the most pleasure for you and your partner. There is nothing more important than self-awareness in sex. You need to know what you like.