Hi OP sorry you have had such a bad experience working in your first care job. I have worked in health and social care for 19 years, first as a carer then trained as a nurse and have managed homes. I left earlier the sector earlier this year. What you are describing is NOT acceptable nor is it standard practice.
Is this an independent home or part of a larger organisation? It sounds to be like there is a deep seated negative culture problem and attitudes as you have described would make me walk away from this home in your position-and I have experience!
Care homes should be able to demonstrate a thorough induction of staff and that includes mandatory training-including moving and handling, fire safety, safeguarding, health and safety etc this is not optional and you should definitely not be working unsupervised to support people to move without this. If you are supporting people with dementia and have never worked in the sector before, as a manager I would also be ensuring you had some dementia training as care for people living with dementia can be complex, stressful and requires a high level of skill. New staff when I was a manager were assigned a named mentor to work through their initial induction which would then be signed off as part of the supervision process if their probationary period was successful. This lasted 12 weeks for full induction and onboarding if there were no issues, but I have extended in some cases. You should also have a named supervisor who will help you in the form of supervisions, appraisals and personal development.
Care homes are generally in a staffing crisis. I would personally find another one because all homes are not like this. Use this experience though to screen potential homes. Ask questions in the interview about what the induction programme is like, what training will you be given to support you in your role and ask to be shown around the home (I am assuming you are being LFTd before going in the building and are double vaccinated). When you look around, look specifically for the availability of staff and crucially where those staff are. In quieter moments, are staff sat away from residents, or are they actively engaged with them? If this is a nursing home, is the nurse out and about or holed up in the office? Do the residents look happy and well cared for? Does the home smell clean? Does the manager know the residents and talk to them easily when showing you around?
Read the CQC report before going, but also check the date that this was carried out to see how recent it was. Things can change between inspections.
Finally, I would also consider reporting your experience and concerns. To whom you do this will depend on how confident you feel in the management of the home or whether you feel you need to speak to someone external to the home. You can report concerns to the regulator CQC. You can do this over the phone or on the website.
Care needs people who are kind and compassionate OP. I have worked in some incredible care homes and can say hand on heart that not all homes are like this. If you really want to work in care, find a home that will help you grow into the role and support you properly to provide the standard of care people deserve.