Because of gates it dosnt really matter where you build your base, My suggestion would be to build your first close to access to the ocean close by the spawn point.

As you explore you will start setting up a gate network to be able to quickly go anywhere on the map so it dosnt realy matter much where your main base actually is so dont worry all that much about it.

Just build a starter base at spawn and wait untill you come upon that special place that speaks to you "BUILD HERE!"

As for biomes, I would suggest you build in the medows or the mountains, not so much for itrs resources or stuff like that but for the lighting.
Medows has a very nice light, it never gets gloomy and even at its worst it has a nice feel to it.
The mountains has the same type of lighting, you have to deal with the cold tho so it probably wont be your first base but its really pretty and you usually have a real good view from it. Blizards are a hassle, especially if you dont have a powerfull computer but its still nice to be there.

So why not the other biomes, the black forest is very gloomy, its anoyingly dark at night, very gloomy at dawn and dusk.
The swamp is wet, dark and gloomy at the best of times, you are going to spend enough time there farming for foodstuffs anyways.
Plains is too bright and if you dont cheese it with dirt walls random spawns of fulingar will chew through your base in no time.

Thus my advice, set ut close to spawn and keep a lookout for a nice medows spot that calls to you : )