Growing vegetables from seed is relatively straightforward. However I thought I might provide some pro tips on how to plan your plantings so that you can experience the joy of growing your own but also actually harvest enough to eat.
You may be excited about tomatoes but you aren't going to harvest any tomatoes for several months after you plant. Radishes on the other hand can be ready to eat in a matter of a couple of weeks. The good part is there is no need to choose one or the other. If you plan the timing and harvests and consider the space available, you can plant both tomatoes and radishes and some greens too.
First, let us consider the timing from planting to harvest.
On the left we have a packet of carrot seeds. It says that the number of days to maturity (or harvest) is 75-80 days. Now, here's the thing- you can eat carrots at pretty much any stage. You can eat them when they are babies, just slender little sweet things, or when they are larger and more robust. Most root vegetables and leafy greens are similar. You can eat them throughout their growing stages and somewhat stagger your harvest in that way. On the right side we have a packet of tomato seeds. Those say 75-90 days to harvest. For tomatoes, peppers, squash, cucumbers and eggplant you are harvesting the fruit of the plant. It takes more time to develop the fruit and you are generally not eating other parts of the plant. In the center photo are French style pole beans ready to harvest in just 60 days.
I might plan on planting carrots in an open area of ground while planting beans on a trellis or other structure. Both the carrots and beans would be direct seeded. Meanwhile I would start seeds of the tomato in pots and transplant them out to the garden in a few months. Just as the tomato plant is starting to get really big and taking over the whole area I would harvest the beans and pull the plants out or cut them off at soil level. The carrots I would harvest over a long period. First I would thin them out and eat some as itty bitty carrots, probably straight from the soil, just brushing them off on my shirt. Then I would eat a few the following week and so on. Thus I am not only prolonging the time of my carrot harvest but I'm creating more room for the remaining carrots at the same time. Crowding will reduce the size of any root vegetable so leaving them enough space to develop is crucial if you want to have a few get big enough to look like your familiar supermarket veggies.
Tomatoes are by far the #1 edible plant for home growers. They outsell all of the other veggies by far. But if you really want to grow more of what you eat or provide for your family's food security you should think about growing a variety of crops. For beginners I highly recommend radishes and lettuce. Both are easy and quick. Squash are another easy to grow, high satisfaction plant. Generally I would wait until May to plant my squash so no rush on those. Another word of wisdom from an experienced gardener is don't plant too many squash plants. You really only need one or two zucchini plants, tops.
If you have a really large space you can always grow more and plan to give away your surplus. You can 'plant a row for the hungry' and dedicate a certain amount of space for food you plan to donate to a food pantry or similar organization. The future is certainly uncertain right now and there will continue to be a need for donations and gifts of fresh healthy food. So plan ahead and then go out and get planting!