What can happen if I ignore my food allergies? Blood test showed that I'm allergic to beef, pork, and gluten among other things. I'm 22.

Consultation. Food allergies by blood testing can often lead to false positive results. It is important also to note whether this testing was an ige or and IgG blood test. Tests alone can not be used to managing food allergies and it is imperative to speak to a board certified allergist to present your signs and symptoms in addition to your tests and come up with a plan of management.
Food Allergy. Food allergy diagnosis is very challenging. The key to making an accurate diagnosis is the clinical history and using skin testing or blood testing to confirm the suspected allergen. Food allergy testing in general runs very high false positives - nearly 40 -60%. You need to speak with your allergy doc to understand these result correctly.
Food allergy. Ignoring foods that you are highly allergic to can be disastrous and lead to severe morbidity or death. The real question is whether you are really allergic to the foods that have shown up on blood test. It is imperative that a proper history be taken, preferably by an allergist, and then selective allergy testing - skin or blood, be performed. If tests are equivocal, an oral challenge canhelp.
Food allergy. If you have not had a problem with a particular food, you may not be allergic to it. Indiscriminate blood testing for ige antibodies to foods leads to many false positive results. Igg testing does not have any predictive relevance to food allergy and should be avoided. You should discuss this with a board certified allergist.
Big picture. Scientific blood tests from accredited labs for allergy-type antibodies against various foods are notorious for giving worthless information. You've probably been to an allergist; if pork and beef don't make you sick, enjoy them. Gluten sensitivity is a special case; if celiac disease is a consideration, ask about a workup for it.