Buy your own copy of the Code of Canon Law. Plainly Catholics may not receive communion in a Protestant church, as what they understand is merely a symbol and the 2000 year old Cathoich Church clearly and unwaveringly understands that Holy Communion is the Body and Blood of Our Lord. Buy a copy of "Faith of our Father" as well.
With all due respect, the Catholic church is not 2000 years old. Perhaps 1700 years, but there is nothing to suggest Catholic doctrine and tradition was present in the early church after the death of Christ.
It gradually evolved later.
' in a Protestant church, as what they understand is merely a symbol'
Not all Protestants believe this.