Please help me run a competition on Facebook!

[ChangesAt30]

Need to do one for work but never have before. I don't use social media myself so always feel a bit clueless (work is aware of this! But no-one else is showing interest in expanding our online presence which is a whole other thread )

Will be giving away a popular item that we sell.

So I know I need a catchy status/photo of giveaway item to catch people attention.
I'm going to ask people to answer a question in the comments. Should I be getting them to 'like and share' the post too to maximise more people seeing it? How do I know they've liked and shared it?
How long should the competition last?
Finally, how do I fairly pick a winner?

Thanks for anyone who can help! I'm hoping to do this regularly but just anxious about getting the first one right

Facebook probably has rules about competitions. Don't think they allow 'shares' as competition entries.

You could allow it to run for a week.
Assign all entries a number, then use a random number selection program to pick the winner.
You can show it over Facebook live by using Facebook on your phone and the number selection program on a PC.
Makes it all clear and 'above board'.

Should I be getting them to 'like and share' the post too to maximise more people seeing it? How do I know they've liked and shared it?
How long should the competition last?
Finally, how do I fairly pick a winner?

As per FB rules you can ask for comments and likes of the image. You can’t ask for shares as a condition of entry but I tend to say “we won’t ask you to share but would really appreciate if you would”.

Make it clear you’re not affiliated with FB in any way.

Keep a record of new likes and comments. Make sure you respond to all comments - interaction helps post reach.

Pick a winner via an online picker.

I always get people to tag a friend in the comments, like the page, then assign a number to each person and get a random number generator to choose and film it so it's quite transparent.

Here you go OP.

Oh thank you all so much!

Enter the details on competition websites for free like prizefinder

See if you’re eligible for a HUKD competition post as they have a huge audience.

www.hotukdeals.com/tag/competitions