In your spare time you might want to go cycling in the beautiful countryside around Ubud. Its easy to hire mountain bikes in the area but make sure that the bike is in good shape. You can sometimes hire road bikes but the variation of terrain suits mountain bikes better.
Ubud is a hilly part of the country so you have to take that into account when you choose your route. Sometimes you have to get off your bike to negotiate steep parts but it is a small price to pay when you are passing through a tropical paradise.
Some just get on a bike and ride wherever it looks interesting but it is handy to use applications like Mapmyride that are full of route suggestions.
Bali traffic is used to dealing with scooters etc so is very considerate to cyclists. They can see you are a foreigner and will generally be extra careful to keep clear of your path. You don't have to worry about much traffic once you are on the smaller side roads further away from Ubud and you frequently find off road tracks or very small roads used only by scooters. There are so many places to stop for a drink or snack as you roam around and the people are very friendly and greet you warmly as you pass through areas off the beaten track.
Do try and get a map of some sort. It may not be fully detailed but will give you some idea of your location. A phone with a compass and applications like Google Maps helps too. You might also download an application like Strava that will record your trip and if you get stuck you can follow your map back home.
Don't forget a helmet and bike gloves to protect your hands. You should have one or two spare tyres, a pump and a small number of tools. Remember to take water. It can get hot out there. Sunscreen, a hat and maybe long sleeves are advisable if you are fair skinned. It is a good idea to give somebody an indication of where you are going and to make sure your phone is fully charged.
Oh yes. You will need sunglasses too.
Before I forget, try to ride from early morning till about midday. Afternoons can get hot and during the rainy season you are more likely to experience showers at that time.