Questions are fine. We are here to help.
There are actually two different portals in Fluorite Plains; Temple of Dreams and Ficho Tunnel. However, if you want an easy way to Bonfire, you can hit your "B" button or click on the feather at the bottom of your FeralHeart tab. From there, you can go to the 'Home' part and if your Home is set to "Lonely Cave" then "Go Home". If it's not, you can select the "Reset Home" button and it will change it back to Lonely Cave for you.
Now, there are four portals in Lonely Cave: South Pole, Ficho Tunnel, Cape of Distant Worlds, and Ascension Island. You will want to go to the Ficho Tunnel portal. It is a black portal, not with the ones with the crystals in front of it.
Once you enter the Ficho Tunnel, you are in water. Go straight and up on the ledge thingy. Do NOT go down the waterfall. If you follow the path, you should find another black portal. That is Bonfire Island.
The total of public maps are: Fluorite Plains, Bonfire Island, Ficho Tunnel, Cape of Distant Worlds, South Pole, Ascension Island, Last Cave, Atlantis, and Sky's Rim. Based off of your post, you've been to Fluorite, Temple, and Cape. With my description, you will be able to go to Ficho, Bonfire, and Lonely Cave. This is where exploring comes into play. If you want help on getting to the other places, send me a PM or add another post.