Being a photographer these days is really competitive business, as warned by Hackamore. I consider myself an amateur photographer, but photograph is a big passion of mine and I am working to build up a name:
1) I have an online portfolio - put your best work there and make a good website, some people go specifically into nature shoots/ fashion shoots, but it's good to have a range.
2) Help your friends or charge them at a low rate. Eg. If you know someone getting married or they have a bakery, offer to help them take some shoots in return for a small fee (or none) and crediting you as the photographer. If they like it enough, they will refer future clients to you.
3) Submitting photos to competition is another way to build up your reputation, if you do win or get honourable mentions, chances are that it can be put in your portfolio and people may even contact you if they like your work enough.
4) Do a project, if people like it enough, it can go viral and propel you to a wider community. (see those Buzzfeed post, some allowed enough coverage for amateur photographers to transition to pro)
5) As mentioned above, help out a professional photographer or get an agency.
Have a read at this article