Here are some ways I've used social establishments from my WOD games set in historical settings which allow my players to exploit and influence mortals:
When coffee was first brought over from the Americas in the 15th Century, it was seen as a novelty and indulgence. That quickly changed in the years to come as the emerging middle-class in Europe acquired a taste for the stuff and mixed it with spices, sugar and milk. Establishments were founded to serve the coffee-drinking culture and this is where the learned and merchant men of the day would gather to gossip, discuss politics and ultimately, make under-the-table deals and negotiate business transactions. This is an EXCELLENT place for historical Kindred to gather and there's no finer place (other than England) in Europe to do so (and do it big!). Serious people frequent these places and a social-focused Kindred will do well here, especially those on the Humanity track or who are Road of Kings (Serpents too!).
For the women of the day, one of the most popular places to go was at the Salon: a place of the most sinful gossip, games of chance, and an abundance of the elite and the beautiful who would come to be pampered and harpy here. A great place for female Kindred to hang out, Torries, Blue Bloods and Loons will especially love it (even Serpents might find something here!). Be careful though, a lot of these women are attached to, married to and/or related to powerful noble or merchant families, even royalty!
For the lower classes who had no way to afford the delights of Salons or had the money or education to back them up in the coffeehouses, pubs were the next best thing. Brujah will love these place and most likely frequented them even when they were alive (except the brew now makes em' throw for an entirely different reason...). Malks and Ravnos can play parlor tricks on unsuspecting gullible patrons, while Tories or those on Path of Humanity can just hang back with their fellow man (while avoiding being stabbed by an angry drunk in the process) and feed on them while they engorge themselves chicken and ale (or cockles and oysters if they're by the sea!).
There's several more I can think of but these should be your players first stopping points for Mortal influence!
Here are some Kindred-specific ways to get influence in Mortal society during the Enlightenment period (this being OWOD, feel free to get ridiculous and gonzo with it!):
Find a person of note in the world and Ghoul them. Be they a scholar, politician, merchant, activist, military officer, doctor, engineer, socialite or artist. Once Ghouled, they'll do pretty much anything you ask, short of outright diabolicalness (and even that can be fixed...).
Have them join debates on the sides most favourable to your agenda, use this to push ideologies on the people in a time where any one idea could spread to become the way forward out of the chaos (Brujahs!)
They can write papers or books to distract Mortals from the reality of the undead that walk among the living through "skeptical inquiries" (You can almost guarantee a Tremere will be doing this!)
Found cults of the occult obfuscated in pseudo-science that implore the wealthy and influential to give themselves over to the mysteries of cult in order get even more wealth and attain even more influence, all the while empowering your Kindred further as a godlike figure (Ventrues, Toreadors, Setites, even Tzimisce and Tremere all do well here)
Infiltrate the royal court and lay rumours, gossip and heresies about opponents and their entourages -- maybe even provide convenient "evidence" to the right eyes. Watch as your PC's rivals (maybe the other PCs perhaps?) find themselves investigated for treason, their businesses shut down by royal decree, their cronies gaoled and their plans ultimately foiled
You're right in supposing that it's a bad idea for noteable peoples to be Embraced -- too much attention. Do the time-honored classic strategy of Embracing -- at most -- rising stars in Mortal world or, better yet, Mortals who are good at what they do and show immense talent but haven't been "discovered" yet.
Remember to ask permissions to Embrace. ESPECIALLY in this time period! You'll get slack in the modern nights but pre-1990's default setting, it's a really bad idea (or not, depending on your GM -- assume it's really, really bad...)
Also, keep in mind who you Embrace. The wrong kind of person will most likely irk those in power once they become known in Kindred society. Larger populations will delay this but eventually your PCs will be held accountable (if this is a setting in which Embracing NPCs is a thing). Foreigners, commoners, criminals etc... all will earn the ire of particularly snooty Cammies.
Remember, in this time period, most Kindred were brought up in a post-feudal world so those old-time traditions still hold weight and inform social custom and tradition, except it's now an aristocracy that holds the true power not the king solely. And church and state is a thing, so having fingers in both pies will pretty much solidify your position between both increasingly secular and religious Kindred. Embrace in both camps and help secure your allies' positions by having them do the same.