30 and 60 seconds countdown timer

First i want to thanks for being here on your great arduino forum. Im electronic technician and found arduino programming over a year ago...now being new to this arduino i want some help (please). I want to make a arduino countdown timer . And here i want to make

A 30 and 60 seconds countdown timer. Selectable using rotary encoder
If i select 30 then press start counts down from 30 down to zero
then shuts off a relay.The menu to select 30 or 60 seconds, and the countdown should displayed on LCD display .

Please kindly help me and provide me a code thank you very much...and please correct me if im wrong to post it here

This forum doesn't write code for you. We will be glad to help you debug/fix your code. Please read the sticky post at the top of the forum about how to post. It will help other people help you.

If you already have the circuit built, provide a drawing of the schematic.

Post your code that you have written that attempts to solve your problem.

I would also suggest that you take this in steps. First get your LCD display working using a library. Make sure you can display "hello world" or something on it. Then get it to display a countdown timer from 30 down to 0.

Test your relay. Get it working. Make sure your code can turn it on and off

Test your rotary encoder. Make sure your code can read the current value.

Then start piecing all that code together. Read the rotary encoder and decide what your count down time is (30 or 60). Turn the relay on, make your code count down. Turn the relay off

This may give you ideas: Relay Timer with LED Display – Arduino++