The breakdown of how many Legend Tokens you get

Apex Coins can be purchased with real-world money, or earned as part of a purchased Battle Pass. They can be used to purchase cosmetics from the Featured section of the Store, purchase Apex Packs containing semi-random cosmetics and sometimes Crafting Materials, or unlock new Legends.

Legend Tokens can only be earned by leveling up (or refilling your XP bar at max level). They can be used to unlock new Legends, or purchase cosmetics in the Exclusive section of the the Store.

Crafting Metals are randomly included in some Apex Packs. 45 Apex Packs can by earned by reaching certain player levels, or they can be purchased with Apex Coins, or they can be earned as seasonal and Battle Pass rewards. Apex Coins can be used to directly purchase any generally-available (not exclusive or seasonal) cosmetic item in the game from the Armory and Legends screens.

There is a chart for this available on this website here with more details, but it works like most battle royale games, having each round increase the damage taken per tick outside the ring, along with decreasing the time it takes between each round as the rounds progress. The amount of damage per tick for each round, there being 8 rounds, works like this:

Rounds---Damage Per Tick

Round 1- 1 Damage 
Round 2- 2 Damage
Round 3- 5 Damage
Round 4- 5 Damage
Round 5- 10 Damage
Round 6- 10 Damage
Round 7- 10 Damage
Round 8- 10 Damage

I hoped this helps you get a better idea of how much time and meds it will take for you to get from one ring to the other!