There may very well be no British ever ITTL. The English-Scotch union was an accident which may not be repeated here.
If the stories about "Basque/Breton/Welsh/Portuguese etc. fishermen in the Great Banks" are true then NA will be "discovered" in the 1500s and explored from the top down, by NW European polities. North America, mind you. Finding
South America may happen several decades later.
Figuring out the currents and winds may take longer than in OTL with no Portuguese precedent of the Volta do Mar. Example - to go from France, England or Netherlands to New York you do not sail due west - you sail SSW as to catch the southern part of the North Atlantic gyre and favourable winds in the neighbourhood of the Canaries. The triangular trade - Europe to West Africa, then North America, then Europe - followed the winds and currents.
It took the Portuguese decades of systhematic, state funded exploration to figure out how to get to West Africa by sea and back. With their camels the Maghreb Arabs never cared about a sea route - in spite of being able to raid Iceland for slaves. Or set up a slavers' base in the Bristol Channel. If it ain't broke don't fix it - salt went south, gold came north across the Sahara just fine.
Enlightment? That's 1700 in OTL. And this is such a different world that there may be no Reneiscance, no Reformation, no whatever