White or black patches on the bottom of the tomato are known as Blossom End Rot (BER) and usually indicate a lack of nutrients getting to the tomato. It can be due to a calcium deficiency or acidic soil, or poor growing conditions. Sometimes it clears up on its own after the first crop.
Determinate tomato plants will produce a single large crop in a smaller space. They can be easily grown in common tomato cages and then removed when production declines. Indeterminate tomatoes, which include most heirloom varieties, continue to grow throughout the season and are especially productive where the growing season is long. They will require staking, pruning, and tying, or a more robust custom cage to keep them upright.
Hybrid plant varieties do not come true from seed, and seedlings will produce mostly undesirable fruit and/or off-type flowers. Open pollinated and heirloom varieties have been selected over many generations, and you can plant the seeds to get the same type of plant again.
What could you compare to a ripe tomato, fresh from the garden? Tomatoes are consistently one of the most popular edible garden plants, grown all over the world, yet most people have only tried a bland handful of the thousands of varieties available. For decades tomato availability was controlled by canning, shipping, and mechanical harvesting and processing needs, but now we're finally seeing a return to the flavors, textures, and versatility that made tomatoes so compelling in the first place.
Consider drip feed or soaker hose watering to efficiently keep your soil moist without encouraging foliage diseases. Mulch can increase the effectiveness of these watering methods, feed the plants, protect the roots, and trap soil-borne diseases and pests away from the foliage.
Aphids come in all colors, including green, yellow, red, and black, doing damage primarily to young, tender foliage and buds. They're defenseless and can easily be squished, brushed, or sprayed off. Insecticidal soap sprays and oils may be used as well, but they will harm your aphid predators, too. Control for ants in the area, since colonies often spread aphids, protecting them and feeding off of the sticky sweet substance they produce.