@Savage281 i'm afraid i don't have any great advice at your level. However, i do want to tell you that as f2p, you can absolutely get higher in the rankings. This is me, https://swgoh.gg/u/sfenrir/ absolutely f2p, but i've just been at it for longer. Patience and playing efficiently will work.
I was always around 20 to 50 range, 'til the rex anti sith meta came to play, since then always in top 20. eventually found my arena mates and it became much easier. there's simply no team that i cant beat on the top end. You will get there too.