It astounded me how little effort and know how was required to do the jobs that ExH used to do. I had, for example, never mowed the lawn. Every job like this that he traditionally used to do he would Lord over me when he wanted to push a view that it was ME who was lazy and selfish, was in fact easy when I tried them myself. 'You never do X job....' I remember fixing the drain pipe back to the exterior wall that had come away. It was a simple job that took a few minutes, but had my ExH been there, he would have used the job as capital to beat me with. ExH did also do 'gendered' jobs like the washing - it took me a while to spot that he only loaded the machine, he didn't sort, fold, iron or put away. But he was able to claim 'I do everything round here, I do the washing, you do sweet fa' (Far from true, actually)
But when you are in the position of not knowing this, it is a scary and frightening place to be. But don't worry, you'll get there. B and Q have videos on you tube on how to do most jobs like taps and tiles and door locks.
Living practicalities like this can probably wait though, you need to concentrate on yourself and your mental wellbeing first. I remember feeling terribly guilty about moping about doing nothing and feeling miserable, but you need to do this, it is part of the grief and you have to go through it. Far more than the simple know how, you need the mental energy to carry on. You need the time to grieve.