Hi Alexis, welcome to your pole journey and Studio Veena! Here are some responses to your questions, I think you will find this website a great resource!
1) Depending on the pole's finish, rubbing alcohol is I think the most common cleaner used. I've also heard of white vinegar or vodka, these however are often claimed to help with grip, too. I use a combo of 97% rubbing alcohol and white vinegar.
2) Again, some have claimed white vinegar helps with grip. You can wipe the pole down with it or dampen a rag and rub directly on hands. Everyone's grip challenges are different, from being too dry or too sweaty (my biggest issue). There are a multitude of grip aids made for poling and everyone has their preference(s). However, the nervousness will subside as you gain confidence and also you will build grip strength with practice. Grip aids are helpful but if you become reliant on them, can hinder training true grip strength.
3) Yes, as you see above, rubbing alcohol is in fact the most commonly used for cleaning poles.
4) I would suggest that you stick to conditioning and flexibility stuff when you first get your pole, especially as a brand new learner. Veena has plenty of ideas and her program is progressive, so you get an idea of what you should be doing. She even has a 30 day take-off for new polers. If you are a home poler, I highly suggesting trying her curriculum out. You don't want to risk injury from trying things that are too advanced and slow or hinder your pole journey before it even starts. It's tempting to try all the "cool stuff" first, but a good foundation is the most important and learning to make the "basics" your own style will make you a better dancer in the long run.
5) Personally, I think a 3 hour training session as a beginner is a bit much. I've been poling two years and 3 hours would kill all kinds of body parts on me! Perhaps taking it slower would be the safest route. Additionally, the grip gloves are good for training new moves where you really need to be able to rely on your grip but I don't think they are the best bet for beginners. Just like grip aids, the gloves can hinder you from developing grip strength that only plain old hard work and practice develops.
6) There are tons of website's for pole wear and gear. You'll find that everyone has a different style, I like a nice comfy bralette and yoga shorts over costumes when I train. But I know badkitty.com has a lot of fun dance outfits and they also carry the Pole Fit line, which are pole outfits exclusively designed for pole dancers. You will see that Veena wears a lot of stuff from Mikayogawear.com, they too have a line designed for pole wear. As you progress you will find that the more skin exposed is better for gripping, generally a sports bra and shorty shorts are the basics.