Hello,
for flashing htc phone first you need rom with specific carrier rom.
ok so you don't know carrier?
here is no problem just make gold card with hxc tool then flash phone.
where can i get roms for my phones?
for roms google is our best friend,but you can check
Shipped ROMs before
.
if you face any type of problem in flashing you can post here,we will try to fix that.