My cbc results are wbc of 3.5 (low), rbc: normal, hemoglobin 12.3, mch of 25.2 (low), mchc of 31.5, rdw of 18.4 (high), neutrophils 21, lymphs 74, ?

So your absolute: Neutrophil count is low -- 3500 x 0.21 = 735. If you have had infection or mouth sores it should be worked up, otherwise the test should be repeated in 7-10 days. May just be a transient finding.

Need a work-up.: You might have one or more issues here. You have a low WBC count with about 75% lymphocytes, which can mean a leukemia or lymphoma. In addition you've a high RDW and low mch, with a normal rbc count which can mean that cells are being pushed out of your bone marrow by whatever is affecting your wbcs. You should see your doctor for more tests, a look at your blood smear, and a full work-up.