Do the Sunnis know how some of God's attributes are, such as His being in front of the worshipper and above him at the same time?

The nature of Allah Almighty's attributes belongs to the unseen, known only to Him, glory be to Him. The People of the Sunnah affirm the attributes mentioned in the Qur'an and Sunnah, both in لفظًا (wording) and معنًى (meaning), but they do not know their كيفية (howness or modality).

Qawam al-Sunnah explained that the created being cannot know the howness of the Creator's attributes because it is unseen, and because the Creator's essence does not resemble the essences of created beings, similarly, His attributes do not resemble theirs. For example, istiwa (Allah's ascending over the Throne) is known, but its howness is unknown, and its knowledge is entrusted to Allah.

Shaykh al-Islam Ibn Taymiyyah said that the Imams deny the servants' knowledge of the howness of Allah's attributes, emphasizing that none knows how Allah is except Allah.

As for likening the believers' vision of their Lord to the sun and moon in the Hereafter, this is not a matter of describing the howness of Allah's attributes. Rather, the similitude pertains to the vision of the seer, not to the One being seen Himself.