kaygisizugur wrote:i have a esp 12 e dev kit v0.9 version
It looks like (actually it's a wild guess) you're talking about a NodeMCU, if not: take a picture of it and post it here (or post a link to the website you bought it).
If it's a NodeMCU (or similar): those have a UART-USB chip on-board, so you can't use TX and RX without (physically) removing that chip first.
When you're new, don't start with a separate ESP (ESP-01 to ESP-14) module.
Get yourself a proper development board: NodeMCU - WeMos D1 - WeMos (UNO form factor) - Witty Board
ESP power requirements are 3.3V±10%@350mA
The ESP8266 IS NOT 5V tolerant on ANY pin (see item 5.14 on page 25 of the FAQ)
The ESP8266 RX pin will look like it has a 470 Ohm pull up resistor connected to the pin. (470 Ohms driven high by the USB-serial chip)
Configuring the ESP8266 RX and TX lines as basic I/O can be found with a search. This has been answered before. And you didn't say what software framework you are using.
The 470 Ohm resistor connected to the rx pin of the USB-serial chip, connected to the ESP8266 will no effect in most cases.