Better for 1 practical endorsement and 3 sciences or 2 practical's with 2 sciences

Hi, I am also a private candidate. I was going to do 3 A levels but found it too much with work so I did 1 last year and doing 1 this year. Looking back, I wish I had taken one of the access courses instead that give the same amount of UCAS points as 3 A levels because I am applying this year and am worried I won't get in. My advice would be to email the universities that are doing the course you want and ask them what you need to achieve before you pay out and commit. For example, I have been told by some universities that I can get in with 2 A levels because I am a mature student but I must achieve an AA unless they are my first choice for uni, and I got a B last year so that's out, wheras another university said they would only consider candidates with 3 A levels even though there grade boundaries are not as high.
Another thing I wish I'd done looking back is finding out all the dates in advance because online colleges will not tell you. For example, the online college or the exam centre will not tell you when your A-level results are in, you only get a certain amount of time to appeal the grade so its important you check as soon as they are out. Also some colleges might tell you there deadline is so and so but due to amount of students or if the tutors are bank staff, they might still not get your work marked in time for exam centre or UCAS etc. Basically, with the online colleges and exam centres, I recommend giving extra time for any request you make so they have time to sort it out and also remember to hound them if you don't hear back from them. For example, if you need a predicted grade for UCAS, get those assignments in at least a month in advance and tell your tutors in advance you want predicted grades as they will need to process it through the college, have time to mark it and grade you. Some tutors really care, some online tutors will not as much - don't be afraid to contact the college head of department if your tutor gives vague and short responses to your questions when your stuck too.
I think you might also need to book your exam centre before a UCAS application even if the exam booking deadline is after because UCAS asks for a number for exam centre. Some online colleges will organise this through the ones they use (you still have to pay), however check the location of this as my nearest one is a 1.5 hour drive into the city which is expensive to park and often has lots of traffic and difficult to navigate, so I need to look elsewhere.
Also, keep all your exam certificates for GCSE, A-level, any additional courses with dates you started/finished/and whether they were with AQA/edexcel etc because you will need these when applying to UCAS.
Good luck.