Starting out in road cycling – building up fitness and distance tips?

I find thinking about the
I find thinking about the quality of kms you are riding rather than the quantity a good starting point- for example I am doing a 110km hilly ride in July and a 140km one in August that is less lumpy-it is the shorter of the two that I need to train for. So think about how flat your routes are before getting too worried about distance at this stage- 10km with hills could benefit you more than 25km or rolling roads.
I find the best way to build up distance is to map out a few loops that you can do- this means it is easier for me to get the kms in before work because if I am in a rush I can do a loop maybe twice, or if I have a later start then I can do it a few more times. That means you are never too far from home at any point which can be a useful in case you bite off more than you can chew. I have a variety of loops- one nearly flat which is good for building up core speed and for recovery rides, another with a hill that has a loop at the top, meaning I can practice my climbing by repeating it as often as I need to but still a relatively short distance from home.
The best bet is just to get riding- you will find that you build the miles quite quickly-a person I knew struggled to do 6km but after a couple of goes he was then up to 32km- once you break the 20mile barrier in your head you will find it easier to rack up the mileage.

I used to have issues reaching down and drinking but again it is more mental than anything. You can get bottle cages that allow you to take the bottles from the side which can make it slightly easier, but really it is just practice. It is also about reading the road ahead and timing your drinks so that you don’t suddenly come on a pothole when you might not have as full control of your bike as you would like. But practice it on your own first before going out in a group-I have been on some sportives where people have been training on their own and never ridden in a group before and they suddenly realise they are unable to drink because they are afraid of causing a pile up. If you do it often enough though it does become a natural action-if you have two bottle cages see which one works best for you- either the one on the seat tube or the down tube-I have always found it slightly easier to reach for the downtube bottle, so I make sure that it is the one I favour, then just switch bottles between cages when I can after the first is empty. It really is just a confidence thing and finding out what works best for you. The longer you spend on the bike, the easier the stability will become.