-First you all, you need to learn Pinyin. Pinyin is a good system and easy to learn, but has its idiosyncrasies. Don't rely on Pinyin, however. Pinyin is an input method, not Chinese, and nobody actually "reads" Pinyin. You need to learn the characters. 

-I started using LingQ, as there were very easy dialogues and audio recordings there. That got my started on the very basics. I would learn the new words, characters and listen to the dialogues again and again.

-I then bought a series of beginner readers called "Chinese Breeze" 《漢語風》, but I'm sure there are others available. I spent a few months on those, continuing to expand my vocabulary, learn new characters and work on my listening.

-I then moved onto a great little book on Chinese culture published by Yale, called "Twenty Lectures on Chinese Culture" 《中國文化二十講》. This, too, was written for beginners in a basic style and came with vocabulary lists. I got a friend to record it for me and did the same thing. 

-Now I had a basic grasp of Chinese, I tried speaking to people on platforms like iTalki, at meetups and to my friends.

-Since then, I have continued using the same approach, speaking, listening to and reading more Chinese and continue to improve. 

There is lots of good stuff on YouTube about Chinese. Steve Kaufmann has done some excellent videos, but there are many more. 

Chinese Grammar Wiki contains some excellent information on grammar points, all in English

The dictionary app Pleco 

Websites like zaojv that are full of example sentences in Chinese 

I read (and still read) a lot of Japanese manga translated into Chinese as these are much simpler than books but still interesting

Laurence