Hello and welcome to APUG.
I'm a Tachihara 4x5 owner and I recommend a 90mm, 135 or 150mm and 210mm 3 lens kit for the camera. That gives a nice spacing between focal lengths. The 90mm is the most popular wide angle for landscape and it will work fine on a flat lens board on your camera. The 135 or 150 is a normal lens and the 210 is an inexpensive long normal lens that is very popular for portraits. It's just a great general purpose focal length. I don't know if you want to do head shots or head and shoulder shots. Most people prefer a 300mm for that but you can't close focus a 300 due to the short 13" bellows draw on your camera. You might pick up a cheap monorail for close up portraiture. I would recommend a normal focal length (135mm or 150mm) or the long normal 210mm for your first lens. Wide angles are a little harder to learn on.
Look for Fujinon, Nikkor, Rodenstock, Schneider or Caltar lenses in modern Copal shutters for your camera. Don't worry about brand (they are all fine lenses). Look for condition and price. Your camera takes Linhoff style boards. They are available new and cheap from Badger Graphics or used on Ebay. You can easily mount a lens using a lens wrench. The cheapest ones are made from a flat sheet of metal and work great. I know B&H has them among other places.
Any of the modern plastic film holders from Toyo, Riteway, Lisco, etc. work fine. There is no Tachihara specific holder. Just look for ones made to hold 4x5 sheet film and are in good shape with nice tape joints so they don't leak light. If you buy new, the Toyos are said to be the best today.
I'm also a member of Large Format Photography Forum. Click on the link that Rick A nicely provided and check out the home page for a wealth of free information. I also own and recommend the Steve Simmons book, Using The View Camera, which Konical wisely recommended. Steve's book is easy to understand with plenty of photographs and is available at Amazon.
The most important advice any of us can give you is to just have fun!