Hi @Adel Bannour, and welcome to the Stake Community!
Understanding Promotions
There are several types of promotions, and you'll find most of the information about them at this address: https://stake.com/promotions
Everything is clearly indicated: the multiplier to reach, the minimum bet, the conditions, etc.
Promotion results will be posted directly in the "Promotions" section here: https://stakecommunity.com/board/30-promotions/
I also recommend searching for your Stake ID on the forum in the top right corner.
It's good to know that some promotions or events are sometimes only available on the forum and don't necessarily appear on stake.com Don't worry, if a bonus goes unclaimed, support will contact you to let you know.
Tips and Strategies
To my knowledge, there aren't any specific tips, other than to adjust your bet according to your balance. I'll let other members advise you further on this point.
Checking Your Betting History
You can check your betting history in your account by going to Transactions, then Bet Archive (you'll find all your old bets there). Your bets for the current day will be available in your account under My Bets.
For opening files downloaded from "Bet archive" you can refer to this tutorial: https://stakecommunity.com/topic/43259-how-to-readfind-your-old-bets-in-a-easy-way
Looking forward to hearing from you!