(Follow Up Post)I had trouble doing that with diamond armor. Stupid creepers....My main priority is getting iron gear. It provides enough protection that you can survive most hostile mobs.
How do you get to level 30? I think the highest I've managed to get was around 16. Then I got killed by a stupid creeper....After that I go for diamonds and an enchantment table, preferably with full bookshelves. Then I cycle the 30 level hint until I can guarantee Fortune 3 on a Diamond Pickaxe. Then I do diamond mining. I use those diamonds to make armor, and I cycle the enchantment hint until I can guarantee Protection 4. Then I use enchanted books to improve my armor pieces.
What is a mending villager? I don't think I've ever seen one of those....
Along the way I try to get a mending villager so I can keep my powerful weapons and armor intact.
I know you tried to answer my question, but now it raised more questions! I suppose the first thing I need to do is try and get a mine together to find coal and iron, then see where I can go from there.
Mending Villagers is a term for a librarian villager that sells a mending enchanted book. You can also have Protection 4 villagers, Sweeping Edge 3 villagers, and so on.
Without an enderman farm I usually hunt mobs. However, this is much slower than a monster spawner grinder. If you can turn a Mob Spawner into an XP farm you can farm XP easily. Enderman farms are high level end game constructions, so hunting or a Mob Spawner farm is enough for starting needs.
Hope this explains your questions!