Last I checked matrix servers consumed a lot of resources, because of the federation, on a side note, avoid any Raspberry pi or any other ARM based server, having x86 set instructions opens up the posibility to install a lot more software, that is if you're a beginner, otherwise, go nuts with ARM.
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im thinking of linode server, self hosting with home computer is challenge
Search for various VPS ("cheap vps hosting" givea a lot of results) and you'll find some more alternatives to Linode if you want cheaper, just beware the ARM servers, and remember you can always download all the data in your VPS and copy it to an old laptop in your home. Have fun self-hosting.