Want to run a secondary node on a new machine and want to use the blockchain data of existing node

[Bitcoin]

Want to run a secondary node on a new machine and want to use the blockchain data of existing node

I run a lightning node (umbrel, raspberry pi). I wanted to build a secondary node(c-lightning) on my laptop (ubuntu), from scratch. I followed some steps from their github but I'm now confused the the step that says starting lightningd I have 3 questions:

1. Using existing blockchain data: Once I install bitcoin - will it start downloading the blockchain data immediately? And how do I configure it such that it accesses the bitcoin chaindata from my existing umbrel node?

   
   



2. Basics of lightning node: as I understand, following should be the process - I install bitcoin-core(or is it bitcoind?), configure it to access my other synced node, once they are synced, I configure lightning (would need to read up on this too) which would use the bitcoin installed on the same system but it(bitcoin in this system) is accessing its chain data from another source. Is this understanding broadly correct and is there a guide where I could try and understand the basic workings of the layers - bitcoin & lightning

   
   



3. Linux basics & managing clutter: Additionally, since I'm quite new to this and to the linux system in general, is there a way to install the various libraries/tools such that in case I want to undo all the changes, I can remove all the installed dependencies - like a virtualenv. Basically, if I decide to start afresh - can I clean the slate - remove all dependencies and start again? As of now I removed the tools I'd installed(lightning ppa, lightningd, bitcoin-core, snap) and also deleted the .bitcoin directory manually.

   
   

Thanks in advance, consider me a n00b who's willing to read up and learn.

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