As the saying goes, they are overworked and underpaid. In fact, most are not paid at all. Some even fund their ventures personally. Others will consider genre stories if they are done well and appeal to a wide audience. Credits in these magazines appeal to editors who acquire book length manuscripts.
Most publications offer both regular submission guidelines and contests for specific categories.
Reviewing the publication prior to submitting is a must. Checking guidelines before submitting will clear up any confusion about payment, which can vary. Token payments or payment in copies is typical, but some small press publications pay well. Writers who submitted to my magazine ranged from raw amateur to near pro. As in any business, there were a few bad experiences with unpleasant personalities.