Your friends are your first viewers. They can give you feedback and recommend your stream to others. But as many new streamers know, getting an audience from scratch could be difficult.
Find out who follows similar streamers
Some viewers like jokes or emotional reactions, others fond chatting and storytelling. Understand what suits you more and search for similar streamers. Learn what you can about their followers. Chatroom and comments on social media could give some understanding.
Network and promote
Posting Twitch link on random chat won't get you anywhere. Maybe a few people will check your broadcast, but more likely you'll get banned. But if you are a part of the community and others are familiar with you, it could work.
If you have an opportunity to pay for a promotion or mutual broadcast, chose wisely. Better to get mentioned on a channel with an audience similar to yours. Funny moments compilations also could be a great way to introduce you to new viewers. Giveaways as a tool are still in play, too.
Personal brand and planning
Try different ways of communication. Find what style is more suitable for you. Your central goal as a streamer is to entertain viewers and motivate them to come back.
It can be equally hard to get your first 10, 100 or 500 viewers. Establish a schedule and try to stick with it. Welcome newcomers, read the chat, communicate. In time you will build a small but enthusiastic community. These people will help you to improve the channel, moderate chat and promote you because they like you.