How to get out of Gold rank?

You could take a look into the KoG deck section on this site and see if you can make a deck based on one of those and modify it to your style and options.

Other general tips.

Even if you have a monster with more att than your opponent, you should not blindly attack into that monster if he has a backrow (spell/traps facedown behind him) and if you would not be able to deal with a counter.
Make sure you can afford the attack by having enough counter or protection cards or if you can afford to lose a monster.

Try make a mix of descent att monsters and useful effect monsters that are not too difficult to get on the field + mix enough defensive cards in your deck.
For example enemy controller,
wall of disruption, mirror wall.

Its recommended to keep your deck around or at 20 cards to have better chances to draw what you need.

Dont try to mix too much different things into one deck. Look for synergy.

I hope this helps.

Gold is easy af. I made it to legendary using a cheap Necrofear deck. You just have to practice more and build a deck that can deal with most of the meta. Look into E-Cons and other defensive S/T cards to patch holes. Good luck!

Cheap Dawn of Destiny box alone either Sacred Phoenix or Naturia can make it through to platinum,

stop using 30 card deck and git gud

phoenix or rebd deck with 2~3 sphere kuriboh will do the job I think, sadly I don't have the f*c@in' kuriboh

Hey, i just reached platinum after grinding my ass off through gold. if you want to get out of gold, try focusing on making decks that have mostly 1800 or higher normal monsters or effect monsters and make sure you dont put in too many of them (effect monsters)that are situational. stay away from trying to tribute, add some defensive cards like e-con, or add in trap cards that boost your monsters attack or defense when they are attacked.

Find a really strong deck ( Tier 1 or 2 as people said - GameA's Beck Decks has some) and master it.