what are the advantages and disadvantages of the condom? and do you also have allergies to it?

Answer

Best,

Advantages and disadvantages have already been partly discussed (see other question).

Main disadvantages: not the safest method to prevent pregnancy (can tear, leak, get lost,…), requires some skill and allergy is possible (both in the man and in the woman)

main advantages: protection against STD, pregnancy, easy to use and requires no planning in advance

You can indeed be allergic to latex (and therefore to condoms made from that material), but you can then use polyurethane condoms.