The usual response after someone posts about their first pin is almost always advice related to how they tend to multiply and increase in numbers and to be prepared, have more room, how lonely it looks, etc. A pretty good one radium just posted in the What machine did you bring home today thread was "Remember the golden rule, every pin you own should be touching two others." (https://pinside.com/pinball/forum/topic/what-machine-did-you-bring-home-today-post-your-pictures/page/338#post-5755482)
This got me thinking about how long after my first pin before I got my second, and I was shocked when I went back and looked and it was only five days! I bought two non-working projects that were only two hours away - Also my first double pin purchase (I have had two others since then).