It's especially useful for shutting down combo engines with one or two artifact components, since your opponent can't usually start their combo in response

(According to our data from Cube Cobra, 67% of fixing lands are maindecked on average, but we observed in the prior table that as the density of fixing goes up, the ratio of maindecked fixing does as well.) These numbers are still very rough approximations, but we can draw some safe-enough conclusions about land counts that would, on average, result in constructed-level mana fixing: To emulate two-color Pauper or Standard decks, 60 to 100 fixing lands should be included in 360-card cubes (17%-28%) To emulate two-color Legacy and Modern decks or 3+ color Standard decks, 100 to 140 fixing lands should be included in 360-card cubes (28%-39%) To emulate 3+ color decks in Legacy, Modern, or Historic, 120 to 180 fixing lands should be included in 360-card cubes (33%-50%) That a ton of lands many times more than the 8%-12% included in most cubes on Cube Cobra

After you've tried those basic rules, there are plenty of ways to play, so finding a format that you enjoy is really important when first learning about Magic
The Ringhart Crest forces you to pick a tribe and it can tap for a Green mana that you can only use to cast a creature of the chosen type or a legendary creature
If you simply cast this spell from your hand for 3 mana, it will deal 2 damage to each opponent and each creature they control