Is there a key on my computer that'll let me type in bold?

Select the bold option from whatever program you’re typing in.

There is no specific key on keyword for bold but you can use Ctrl+ B

I think you mean in capital letters. There are two ways,hold down the Shift key and type. Or press the Cap Lock key and it will enable capital letters,press it again to disable it.

Not all programs support bold letters. For instance, Wordpad and Word and PowerPoint will. Notepad will not. Usually, pressing the CTRL and B keys at the same time will toggle the type face from normal to bold and back again. CTRL + I gives you italics, CTRL + U gives you underscoring. But for example, on this page with my browser, CTRL+ B displays or hides bookmark lists, so that doesn't work everywhere. It depends on the program.

It's not a key it's in the font change the font to a bold font

There's no dedicated "bold" key on a keyboard that I'm aware of. That is up to each program you use. On MS Word (and I assume other similar word processing programs), you can press Ctrl+B to use bold type.