Indeed all of the dialects are mutualy inteligible, the basic vocabulary and the standard versions remain quite similar.
My only recommendation is paying attention to idioms, different meanings of the same word, humor and the order in which ideas are organised in a sentence.
Even inside Mexico I find many troubles in explaining or saying certain things with others due most of Mexicans (as most of Spanish speakers) tend to omit certain information or asume their ideas are clearly enough stated. In my defense, I take my time to explain others why things are not so ovious.
Romance language speakers value and defend their views on cordiality and etiquette. Thus they appreciate explanations much more than direct or detailed messages (my personal style, unfortunately).
So, misunderstandings between people of diferent regions and economic groups are quite common and adding the wrong words in the wrong order might be interpreted as offences, arrogance and pity (clearly said or implied in other ideas).
But, you shall not fear. The best you shall do for avoiding those confusions and misunderstandings is consulting any of the all the abundant webpages which explain local specific slang or simply asking for explanations to the local people, most of Spanish speakers prefer giving funny explanations of their slang rather than turning around and leaving you alone to figure out things by yourself.
Some example of vocabulary with terribly different meanings, which you shall be cautious with are:
Peninsular and Colombian highlander vs Mexican = cojer (to handle, to take something, to use something or to choose for something Ex. cojer camino para A= to take a certain route to A , BUT not to use in Mx)
Peninsular & Mexican vs Caribean = bollo (a bread or a ball of non cooked bread, too explicit in Cuba)
Colombian vs Mexican & Peninsular = carajo (any unuseful thing or annoyance in Co, but used for inciting confrontation for certain people in Mx and a larger number of people in Sp)
Mexican northern vs southern = piloncillo (too private for describing it for people in the north, innocent home made sugar in the south).
Mexican vs Peruvian = maleta (a simple lugage in Mx, a prostitute in Pu).
Peninsular vs southern Mexican = hostia (a common religious item in Mx, to beat someone in Spain)
Peninsular vs Mexican = pepe (not going to explain its meaning in Andalucia but it is a common nickname in Mx).