Without photos, it is difficult to diagnose the problem, but we can try to provide you with some information that may assist you. Your Elm is also known as Patmore Brandon American Elm (Ulmus americana 'Brandon'), a cultivar from Alberta, Canada. It is noted to be hardy to Zone 3 and is both salt and drought tolerant once established in moist, well-drained soil. Several growers recommend pruning only as needed in the months October to March.

Ants: Below is a CSU Fact Sheet on ants. Black carpenter ants do not actually feed on wood, but rather create galleries within decaying wood to build their nests. If this is the case, you will see what looks like sawdust around the base of the tree.

https://extension.colostate.edu/topic-areas/insects/carpenter-ants-5-554/

Sunburn: The neighbor may be referring to 'sunscald' which is caused by fluctuating temperatures during the winter. Warm temperatures force the cells in the tree to become active, only to freeze again when temperatures drop. Trees that are 3-5 years old should be wrapped with tree trunk wrap every November and removed in April. Sunscald can cause cracking of the trunk, which then becomes a host for various fungi and insects. There are two links below on preparing trees for the winter, including winter watering.

https://planttalk.colostate.edu/topics/weeds-cultural-problems/2111-sunscald-trees/

https://source.colostate.edu/prepare-trees-winter/

Vitamins: The well-meaning neighbor is probably talking about fertilizer plant stakes. Trees, especially those in or adjacent to a lawn that gets regular fertilization, generally do not need extra fertilizer. Fertilization requirements should be dictated only by a soil test. CSU can test your soil and determine if there are missing nutrients. Soil testing lab link:

http://www.soiltestinglab.colostate.edu/

Bloomed: Not sure what you mean by 'bloomed'.

If 'bloomed' refers to 'leaves': If this tree is two years old and has never leafed out, it is dead. With your thumbnail, you can scratch off a small area of the bark on the branches to reveal the wood beneath. If the tissue underneath is green, the tree is alive. The buds that you mention are leaf buds, and if they are green, that is a good sign that the tree is alive.

If 'bloomed' refers to 'flowers': Neither flowers nor the fruit on this tree are ornamentally significant so you won't see any.