Take your time, there is no need to rush. You really have all the time in the world. This is a very big change, and you may some mistakes, but it will not matter. Have a look at all your local groups, U3A, WI , political groups, craft groups, etc.etc. With these you will find an abundance of groups operating on virtually every day of each week.
You may also like to spend some time on regular charity work, most shops are still looking for volunteers, delivering meals on wheels, your local (sadly these days everyone has one locally) foodbank, Fridge for free. Many parks are run either entirely or part by volunteers.
For the finance side- write down all monies you are receiving. Then write down EVERYTHING you are spending money on - do not forget your own spending money even if it just the coffee you purchase if meetings are held in coffee houses. Provided that the first list is slightly larger than the second one, then (Micawber like) all is well. If not then look carefully at the second list and make as many cuts as possible. Sadly things like payments to charities may have to go, check all your insurances, you have time now to really research the best of these as they come up for renewal. Allow some money for clothes /shoes renewals, but you will not need as much as you did when working.
Again you have time to shop around, and to cook more from basics, you should be able to prune your weekly shopping basket.
Also to remember that as you are likely to be home more than previously, your energy bill may increase - but if this is a serious problem look up local 'warm rooms' in your area.
You should, hopefully, have very many years to live and enjoy this new way of life.