Ascot Racecourse is famous for the Royal Ascot which brings out people by the droves dressed to the nines. At other times in the year the dress code is a bit more relaxed but if you do not dress appropriately you risk not being allowed in. Different enclosures have different rules so do check the website for the rules.
Ascot is two hours drive from Cambridge. Its best to go A14->A11->M11->M25->M4. It does not seem like it would be faster but the M25 gets really busy. Also leave yourself additional time in case there is an accident. Do not park in the places where they charge you, if you keep going around, you will see free parking.
It is also down the road from Windsor Castle so while the racing will take up a whole day, you could try to book a room and stay in the area and hit that up as well.
The website also tells you how to place a bet and all other useful information so I would definitely read everything before you go. If you have been to the Newmarket races then you might know how racecourses operate.
We brought a picnic which we ate before we went in. You are able to bring one in with you but there are only certain areas you can lay this out and you cannot bring seats.
We got really lucky with the weather as it didn't look like it was going to be very nice. We also won a bit of money, which covered our losses. We saw Frank Dettori make a great comeback and Princess Anne! Not a bad day out!
I would love to come for the Royal Ascot and dress up!