There are some (probably many) Asian languages such as Korean and Japanese, and other languages in India, where the first person pronoun 'I' can be omitted, especially in casual conversation, but the context and the verb conjugation leave no confusion about the meaning. Spanish is still very new for me, but I'm guessing that this usage is similar.
Hm, I don't really speak Spanish but that looks like "I only eat lactose-free cheese" which is different. In the UK, we can get lactose-free cow milk based cheeses in regular supermarkets. There are probably even more options elsewhere. This would be suitable for the lactose intolerant but not for people who object to the killing of children so that mothers can produce milk for cheese making. #vegan
"Como" = "like"/"as" but also means "I eat"
Comer = (verb) to eat Como = I eat Comes = you eat Come = you/he/she eats Etc.
So to say "yo no como queso"/"no como queso" means exactly the same thing - "I don't eat cheese." "Yo no comer queso" is wrong, it means "I don't to eat cheese." Hope that makes sense... :-)
First, Spanish may omit subjects since the verb provides this information. Yo no como queso == no como queso.
Second, in English "don't eat cheese" (imperative) is totally different to "I don't eat cheese" (indicative). The former is a command and the latter is a plain statement. Therefore, the translation is different in Spanish too.