AAT Account Level 2

Yes you can study this by yourself, but it depends on you personally whether you would be able to cope, be comfortable, determined, focused and be successful without any tuition etc. If you are comfortable and capable to do learning without tuition then go for it. You would need to register with the AAT as a student which there is some study material you will get access to and a couple of practice papers for each module to see what the exams will be like.
Once you are registered with the AAT you are then able to sit exams. You would need to find an assessment venue to book your exams which the prices will vary and locations might not be local, potentially you might have to travel further away to sit an exam cheaper if price is an issue. There is a page on the AAT website which will give you assessment venues and locations to choose from. There is the possibility to sit some of the exams remotely but depends on the assessment venue/AAT whether they do this but you would need to meet the remote assessment criteria such as a webcam etc so that the assessment can be recorded.
The books you could have a look at getting are the 'Osbourne' books and/or 'BPP' books. Both are good and bad in their own ways, it just depends which one of these you find more helpful and easier to understand. There are some practice tests in these but based on what is in the books and not completely the same style as the AAT exams. You can get these from the company directly or amazon might have copies, make sure you get the correct qualification year books. There are video's on YouTube from places like 'first intuition' which are ok and could be helpful.
If you struggle then it might be worth looking into going down the tuition route which there might be a local college which offers the course either during the day or in some cases in the evening. Otherwise training companies like 'first intuition' etc will have online classes and provide you with some study material and more practice papers etc.