A "standard" schedule would be every alternate week-end Friday (usually from school) to Monday morning school drop off (or Sunday night 6pm), plus one midweek overnight (usually Wednesday and usually from and to school).
If your child is under school age then a schedule can be more flexible but I would think if you have every Friday and alternate week-ends then on your week-end, the Friday should be included in the week-end. Eg Friday morning to Sunday 6pm.
How old is your child?
The only "benefits" affected by you having more time would be Child Maintenance payments. Have you checked the Child Maintenance Calculator to see how much you should be paying? Is there a CMS case open or are you paying by a private agreement?
The way they work it out is a percentage of your "gross" income, and that figure is reduced by the number of overnights you have. So if you had no overnights, your ex would get the maxium amount. The more overnights you have, the less money she gets.
One way round that is to agree a sum of Child Maintenance between you that means she keeps the same amount of money regardless of you having additional overnights. Currently you only get one overnight a fortnight so she will be pretty much on the maximum amount. Unless you are a high earner, then it may not make a huge amount of difference to you, to pay her the same, even if you have more overnights.
This is called a "family based" arrangement. You just agree in writing (eg a text), that you will pay x amount a month in CM, regardless of what the assessment says.