Invictus theme… What have I gotten myself into?

Hello all,

I just bought a custom theme (Invictus) for my wordpress.com site and, am gathering (I think?), that the theme is actually intended for www.remarpro.com.

Do I need to shift my site to www.remarpro.com to use the theme? If so, I must pay for webhosting or provide my own, correct?

Is it possible to use the theme on wordpress.com?

Sorry, I’m sure this is annoyingly basic for most of you. Appreciate any help though!