Here is the thing with online companies:
1. You really should not be interested in creating a forum / blog due to the sole interest of making money with it. It is very possible to do it, however, it takes a lot of time, a lot of effort and a lot of perseverance to be able to make money with this kind of sites.
That's why a blog / forum usually starts with something that has a lot of interest / knowledge. In that way, the profit is not everything, but he likes to update it and keep it running. Later the money will arrive, which in 99% of cases is not a fortune.
2. Having something online to make money is still a normal business. Apart from the fact that you can now market globally instead of locally, you must still calculate that making a good amount of income online still takes time. There is no such thing as making money quickly online unless you are very knowledgeable in certain areas. Unfortunately, one of those areas in which you must have a lot of knowledge is to earn money online. If you still do not have experience in this field, it will take time.
When I started working online for the first time, I could have earned around $ 50 the first month. Taking into account the hours I spend, it really is not worth anything. But I learned a lot from all my experiences, and knowledge is always key.