Here "your coming" refers to when Jesus will come in power, establishing God's reign on earth and bringing this age to an end. AT: "What will be the sign that you are about to come and that the world is about to end" (See: [[rc://en/ta/man/translate/figs-explicit]])
To lead one "astray" is a metaphor, as if the person is on the correct path, but is suddenly led off the path by being deceived. AT: "Be careful that you do not follow anyone who would deceive you about these things" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Here "name" refers to "in the authority" or "as the representative" of someone. AT: "many will claim that they have come as my representative" or "many will say they speak for me" (See: [[rc://en/ta/man/translate/figs-metonymy]])