Well I'd volunteer my services as a second/third shooter to as many local photographers as possible between now and then, if I were you.
And not worry about filters too much - you won't have time to be using them.
I'd recommend, as an absolute start:
To hire a 2nd camera body - for two reasons. So that if something goes wrong with your camera you have a back up and so that you can have a different lens immediately available for a different FoV. As you only have a kit lens, you'll have to be hiring a lens too - I'd probably go for a faster zoom lens in the 24-70 or 70-200 f2.8 range
To have at least one speedlight - preferably two (so if something goes wrong with one you have another spare). There may be times when you cannot use a speedlight and have to run with available light only (maybe the church and ceremony) so you may also need a faster lens to help you out. Be 110% comfortable with using a flash and getting consistent results. This will save time during the day and time in post production.
To have multiple memory cards in case you lose your files.
To go on some available light courses to manage your images during the formal shots and times when you cannot use flash.
To go on some speedlight courses to learn the use of bounce flash (when you're using one flash) and lighting set ups if you're able to set up more than one flash to control light.
Have a crib sheet of formal shots required and shots not to be missed - work these out in advance with the bride and groom, sort out orders for the formal shots so not too many people are hanging around etc should help
Maybe to get some remote triggers for those flashes, if you have them.
And that's the very tip of the iceberg, so filters are the very least of your worries. If you can get yourself to any social functions to practice event photography with bounce flash (shooting manually for consistency) through local clubs/societies/contacts with local press shooters as a second photographer etc, that may help.
So I don't want to put you off (!) but there's a big step up from having a camera at a wedding to being a wedding photographer. You'll have to manage your friends' expectations, understand what style of photography they like (do they like black and white reportage? Will your current kit enable this? Do they like selective colour (if so, shoot them now
) black and white images, what are they expecting from you?)