Customising before moving hosts

Hi,

I’m just setting up a site with WP.org for the first time.

I decided to use free hosting initially but it is really slow even to login to my admin panel, so I will end up getting better hosting at some point soon.

Will this mean I lose any customisations I make through the admin panel? (backgrounds, widgets etc)?

I’m hoping to use a static front page and buddyPress or similar, so if I do some development before switching hosts, do I export the site to keep it all? Or does that just export content?

Thanks for any help/advice,
PP