Great advice above. In regards to the boil. The wort just needs to be boiling; it does not need to be boiling so hard that it is leaping out of the kettle. Excessive boiling results in more darkening if the wort and higher boil off rates.
Looks like you’ve done your homework so have you established a way to cool your wort when the boil is finished?
O2 before fermentation is good. Yeast (especially liquid) need it to reproduce and have a healthy fermentation. O2 uptake after fermentation is bad and results in oxidation which will give your finished product a stale, wet cardboard taste that can also be harsh and more bitter (not a ‘good’ bitter). Avoid O2 uptake by racking/bottling very slowing, minimizing splashing.
One thing often overlook it water, even for extract Brewers. Chlorine or chloramines in water can give your beer a vinyl, plastic, or band aid off flavor. No need to worry though. You can use distilled water or add a 1/4 tab of crushed camp den tablet to your tap water in the kettle and this will remove the chlorine.
Just some additional insight. Welcome to the hobby. Be prepared to hold on as before you know it this hobby will grab you by the ass and soon take over your life. Seriously. It has a tendency to do that.