So I have set a relay node up on a vps. Now I want to connect it to my wallets in order to send transactions faster. How do I do that? Thanks
It is a common myth inside the NFT community that a node sends transactions 'faster' than a wallet. Daedalus is a node itself so there is no difference between sending a TX via Daedalus and sending it via cardano cli wallet aside from a TON more manual effort in the latter and the risk you'll overwrite and lose your payment keys and permanently lose access to your funds... That said, it seems as though you've bought into this myth, so very well.. here are the answers:
First, you'll want to become familiar with the cardano-cli wallet commands. They can be found here, https://input-output-hk.github.io/cardano-wallet/user-guide/cli
Specifically, you'll want to 'create a wallet from recovery phrase' to restore a wallet into your VPS and then you'll want to use the "cardano-cli transaction" command to send a TX to the NFT vendor.
cardano-wallet wallet create from-recovery-phrase [--port=INT] <name> [--address-pool-gap=INT] cardano-wallet transaction create [--port=INT] WALLET_ID [--metadata=JSON] [--ttl=SECONDS] --payment=PAYMENT...
Before setting up your own cardano-node to use it as an submit-api endpoint, you might want to take a look at https://www.freeloaderz.io/. This is a group of SPOs offering to the community submit-api endpoints that users can set in their wallets exactly for this purpose.
If you don't want to create an HD wallet using the command line and just want to submit transactions to your custom node from existing wallets, check this link out on how to connect Nami/ CCVault (Eternl) to your own node.