wifi questions

I would like to add a wifi component that i can connect to my arduino uno board, what component am i adviced to buy .

I would like a wifi component that is not expansive

You might consider getting a ESP32 instead of the uno as it already has the wifi installed on the board. The above link will get you started.

In general, I try to not use the UNO as it is slow, limited RAM and no WiFi. My GoTo MCU is the Wemos D1 Mini. (8266 based, supported by the Arduino IDE). The D1 Mini has 4MB of flash memory, 80MHz clock, 50k of usable RAM and an on chip Wi-fi Transceiver.