I need help.

I am new to rigidchips so I need help as I do not know how to put new vehicles into the game.

File > Load Chips
Select the .rcd or .txt file of the vehicle you downloaded

I cannot find Load Chips

Seriously? Anyways:
1) Start up RC. Check if there's the window around it. If it's in full-screen, press Alt + Enter to exit full-screen.
2) See that bar at the top of the window? It should have these options: File, Setting, View, Regulation, Log, and Help. File's the one you want.
3) Select start, and then select Open chips. A pop-up window should appear, asking which file to open. Find the file, and double click/single click and press 'open'.

You can also use the shortcut Ctrl + O to open chips.

Yeah I know that, but how do I download new chips?

The model will come in one of two formats: .txt and .rcd. either way, just save the file into your data folder, or wherever else you keep you models. If it's in a code box (like models on these forums), just copy all of the text inside the code box, paste it into a new notepad doc, and save it in your folder.