1. Invest in a good set of armour as soon as possible. Armour can be very expensive, especially compared to enchantments for pickaxes. But it sucks to fall in lava, die, lose your enchanted gear and basically have to start from scratch. Mining can be dangerous, but a full protection IV set of diamond armour will make you much safer. 2. If you fall in lava, use /home. Because there's no timer for /home on main, you can use it to get out of danger and save your items if you're ever about to die. This saves your items, but it won't protect your exp if you burn to death. To prevent yourself from dying at all, I'd recommend digging out the block underneath your /home and placing some water there. That way, you'll stop burning as soon as you get to your home. 3. Repair your tools/armour often. Don't wait until your pick is nearly broken - ask for an erep once it's at 1/3 to 1/2 durability. 4. You probably already know this, but sell all your mining stuff at player shops like bedrock or apex for extra money. 5. Mining can make more money earlier in the month. This is because the mining world resets around the 1st of each month. By the end of the month, enough ores have been dug up that it might affect how much you earn per hour. If you aren't earning much from mining right now, don't get too discouraged - mining will reset in about 10 days.
Also, I would invest in Fire Protection enchants if possible, or at least Brew a good amount of fire res potions.