Are lymph glands big with lymphoma?

Maybe. Enlarged lymph nodes (lns) may be associated with lymphoma, but the differential diagnosis (other causes) includes infection, inflammation, etc. Likewise, lymphoma often causes enlarged lns but not always. I have a recent patient with normal sized lns that are pet+ ("active") but with lymphoma in bone marrow. Lns may not be palpable and "hidden" inside body as well.
Yes. Lymphoma, cancer of the white blood cells, dose cause the lymph glands to enlarge, but there are also many other things which can lead to enlarged lymph nodes.