Welcome! I know it can be a bit overwhelming and confusing when you're just getting started. But it's pretty intuitive once you get the hang of it.
Assuming you're using Amethyst, which allows the configuration of different relay types, I would suggest the following as an initial config:
Public Inbox & Outbox Relays
* wss://relay.damus.io
* wss://relays.diggoo.com
* wss://nos.lol
DM Inbox Relays
* wss://auth.nostr1.com
* wss://relay.0xchat.com
Private Home Relays
* wss://relays.diggoo.com
Search Relays
* wss://relay.nostr.band
* wss://relay.noswhere.com
* wss://nostr.wine
General Relays
* wss://relay.nostr.band
* wss://relay.damus.io
* wss://relay.primal.net
* wss://nos.lol
* wss://relay.mostr.pub
* wss://relay.0xchat.com
This is a solid starting configuration that will provide you with fast and reliable note storage, authenticated private messaging, private storage of drafts and app settings, robust search, and comprehensive access to notes published by users across the network.
I would also recommend that if you're using Android, you download Citrine and run a local relay on your device. A local relay will store every note and comment you publish, and can serve as a backup and guard against censorship, as well as deletions by your public relays.
After you've been a user for a while, you may also want to consider paid relays which can offer greater spam protection, faster speeds, greater note retention, and greater security for your private DMs.