I did 2 A-Levels - in that I took 3 because I had to, scraped a pass in AS Maths so I could continue to A2 and then let myself get a U so I could focus on the other 2 because I was working full-time at the same time. It worked, I got an A & a B, but, whilst I'm sure it helped my CV I would only put that down to the fact I got high grades (at the time A* wasn't a thing), and unis then and now won't accept them.
*So honestly I wouldn't recommend it,
There are other Level 3 qualifications you can look at. Is your goal to get into university eventually or be a competitive candidate on the job market without a degree? (because you don't NEED one for a high percentage of jobs - experience and evidence of commitment to a post is better and the quicker you can start to build up some work history)*
*It really depends on what you want to do, but you don't need to take A-Levels to go to university. There are alternatives.
I would suggest speaking to somebody at your school/6th form about your options*