Circumcision (khitan or khatnah) is the Sunnah of Prophet Ibrahim and Prophet Muhammad (peace and blessings be upon them). The Prophet (peace and blessings be upon him) said, “There are five things that are of the nature (i.e. of the natural hygiene): removing the pubic hair, circumcision, trimming the mustache, removing the underarm hair, and cutting of the nails.” (Reported in all the six authentic collections of Hadith and other books of Hadith).
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: Circumcision for males is one of the important rites in Islam. The Prophet (peace be upon him) tells us that it is one of the five ingredients of natural religion and therefore part of the common legacy of Prophets (peace be upon them).

If lack of funds is holding you back from embarking on this procedure, there may be some Islamic centers or mosques that can assist you in this matter. You are eligible to apply for funds from Zakah for this purpose. you may do it either before or after taking the formal shahadah (testimony of faith). However, it is not recommended to postpone it indefinitely after you have embraced Islam.
As a recently converted, you need not worry about the procedure itself. In most cases, it is not at all different from a minor surgery; it should normally take only a few days to heal. So don’t let this thought hold you back unless you are suffering from some severe health complications that may adversely affect the healing process.
If that is so in your specific case, then you need not undergo the procedure. This determination, however, is left to reliable, expert medical practitioners in the field. May Allah inspire us to do what is right and acceptable to Him.