Help with lightning (inbound/outbound liquidity)

I thought I am a somewhat smart guy but I am fiddling around with lightning half of the day and it is a bit hard to wrap my head around it.

I'm running an umbrel server and just opened a lightning channel with 250k sats to test. Now 250k is max send and 0 is receive, so I have to send something out the get inbound liquidity - so far so good.

I can buy the liquidity somewhere or do a triangle swap. Or can't I just send half of it to my muun or bluewallet and somehow get it back to mainchain or fund a second channel with the sats then?

Just trying to find the easiest way for the beginning... thank you!