Most first plants die of kindness. Here is the short version of not doing that.
Most first plants do not die of neglect. They die of attention. Too much water, too many moves, too much worrying. So the first rule is the hardest one.
Water less than you want to
Stick a finger in the soil up to the second knuckle. Dry? Water until it runs out the bottom, then tip the saucer. Damp? Walk away. For most plants on a windowsill that works out to about once a week. Your plant would rather be a little thirsty than sit in a puddle.
Pick a window and commit
Plants hate being moved. Find a spot with good light, put the pot there and leave it. Rotate it a quarter turn each week so it grows straight. That is the only moving it needs.
Look at it
This is the actual secret. Once a week, on your date, pick the pot up. Look under the leaves. Touch the soil. You will notice problems a week before they matter, which is the whole game.
Yellow leaves are a note, not a crisis
One yellow leaf at the bottom is a plant tidying up. Pull it off. Several at once, with wet soil, means too much water. Several at once, with dry crispy soil, means too little. The leaf is telling you which.
When in doubt, do nothing
Plants move slowly. If something looks off, give it a week before you do anything. Half of plant care is waiting with your hands in your pockets.
Write down what you did each week. By week six you will know your plant better than most people know their houseplants, and it will look like it.
Get dirty.
