Never played Fortnite before so everything ist new to me.
How do i see which skins are available and what do they cost.
Are skins Tradrable?

Just Lego Fortnite.

@partank able to help?

Skins are not tradeable, all skins have a Lego variant. Everything costs vbucks or irl cash

is there a shard with all lego skins?

Shard? All existing skins in fortnite have a Lego version. In fortnite you get skins from battlepasses or buying them in the item shop or occasionally through challenges

Thanks for Input.

Not ALL skins have a Lego variant right now but I believe they are working on it. My advice is watch the YT videos that show all the available skins and skim through there.

There was a free skin for Lego in the item shop but it's gone as of this morning. Anyways, see where I've highlighted in red. That's your item locker and item shop respectively. The second image is of your locker. Click the character portrait to change or see your available skins.