Spawn close to a village that got stuck between two types of forest biomes: roofed forest and birch forest. You can easily find it at coordinates 50, 350.
Luckily, there is also a blacksmith in the village with a chest containing obsidian. This means only one thing - there is a source of lava nearby, which you can use to farm obsidian.
For more Minecraft 1.15 seeds, check out the list below: