I can't answer all the questions but I can answer some.
For a starters, you don't NEED dumbbells, you can even do the exercises without any weights as long as your doing the movements properly. But I do recommend using some weights, if you have to you can start with tin food or equal weight, or water in drinking bottles, again of equal weight. I'm sure there is something at home you could use as a substitute.
Secondly, if there are some exercises you can't do, they do suggest easier versions of the movement or you could try a different video as long as its based on the same area of focus, so if its supposed to be core, try another core video.
Lastly you don't need to do the suggested diet plan , but for best results track your foods to watch your calorie intake and try to stay within the limit given to you.
Do that you can and realise every step for the better us progress, so don't overwhelm yourself. There is a lot of resources and support here so good luck!
| current weight: 139.0