Variable star observing is a well established research area which is just crying out for new observers. After too many years procrastinating I start observing last year with a 6" frac from suburban Wollongong. Conditions in Carringbah are less favourable but there are very productive observers who work from even worse locations (eg Manilla). So with your larger scope I think you could go as faint as me, which is about 11.5, though mostly I try to stay a couple of mag brighter than that. For brighter targets I have an 80mm riding piggy back, which gives a wider fov and so is more able to get comparison stars in the same field. (I've found that I'm rubbish using binos so that rules out very bright targets.) You will find that you will have plenty of targets in your range. I'm concentrating on miras, semi-regulars and young stellar objects because they are a bit under-loved these days and, more importantly, they suit my observing cadence.
Observations are submitted to AAVSO, which is also the source of heaps of info and resources. One nice thing they do is send a weekly email summary of downloads of data I have submitted. So I can see whether my data is used, and yes it has been, particularly R Cen and RS Oph.
Locally there is Variable Star South which also has useful resources, newsletter, email forum, zoom discussions and more. They are very welcoming to noobs.
https://aavso.org/
https://www.variablestarssouth.org/
I've spent a fair few hours over that last year putting together resources necessary to support this project and I am willing to share whatever is useful. I've pored over the AAVSO target to tool to compile a list of targets which suit my mag range, latitude and obs frequency. I then make my nightly target list from this master list. Compiling the list was a learning experience but, on the other hand, you may not want to replicate the effort.
The other thing you will need is finder charts, which can be made with the AAVSO chart plotting tool. I've already done that for most of the stars on my list. I've then converted them to suit my technique, which I rather like. I've dispensed with paper charts and torches and view the charts on my tablet which sits on an (otherwise unused) music stand next to the scope. The charts are produced with black stars on a white background. I invert this to white on black and then remove the green and blue channels and cut the red to 80%. With the tablet's brighness at minimum this gives me a red on black image of suitable brightness for my backyard.
If you are interested in this research area feel free to get in touch. Otherwise ask the much more knowledgeable folk on either of the sites I've mentioned.
