The following are completely safe.
traditional plant breeding, where seeds are saved from plants that have desirable properties (vigour, good taste, disease resistance, etc). That process has been practised by farmers for thousands of years and is practised nowadays by seed companies.
"marker assisted selection" (MAS), a recent innovation in biotech where marker genes are used to guide the selection of which seeds to save.
The above methods are safe since they simply shuffle the genes that exist in nature. The human body learned to deal safely with those genes during the last few million years of evolution, e.g. when our ancestors were hunter-gatherers.
Genetic Engineering (also known as genetic modification) is quite different from any of the above and is horribly dangerous.
Like the above, it is used to develop new varieties of plants, but the methods used do not merely shuffle existing genes. They damage the genes themselves. In addition to bringing about the required genetic change(s), they cause massive, random and unpredictable damage to the rest of the genome.
The damage can cause the food to be harmful, even fatal, to those who eat the food or breathe the pollen.
It is similar to inserting a new paragraph into a computer document, but using a faulty word processor that introduces multiple errors throughout the rest of the document.
Pro-GM propagandists would dearly love to blur the distinction between GM and MAS. For example there was a recent article in the Economist under a heading "GM and after" that gave a description of MAS.
MAS and GM are very different technologies. They work in completely different ways. MAS is completely safe. GM is horribly dangerous.
Research these matters for yourself. But be aware that there are websites and other sources of information at both extremes: pro-GM propaganda websites and also the opposite.
If you take the view that there's nothing one can do about it, so one might as well not bother, then you are wrong. One cannot escape GM foods, particularly in the US, but one can do a great deal to reduce their harm.
Be aware that in the US, there is no requirement whatsoever for food in the stores to be labelled as GM.
Be also aware that in the US, there is no requirement whatsoever for a seed firm to inform the authorities (e.g. the FDA) that they are using GM. Even if they do, the FDA do no testing, but merely take the word of the seed company that the seeds are safe.