Take the tickets, it's a fantastic experience regardless of where you are on Centre Court. The first day is also great - there will be so many good matches on the "outside" courts, which anyone can walk into with any ticket, that you'll probably not spend all day in your seat on Centre. Also, security at Wimbledon is super relaxed - if you're high up, then when people leave later in the day you may well be able to walk into some seats which are further forward anyway. In short, seats on Centre are great - enjoy them, but also enjoy everything else which will be going on.
As to how I get tickets, my mum's tennis mad, so when I was a kid we'd go and queue. Back then you could get there at 9am and be on Centre by midday. I've also got a couple of friends who used to work in the industry (a cameraman and journalist) so went a few times with them (sadly Wimbledon has locked down a lot more on them letting guests in now). And Wimbledon is very good at catering to people who play tennis, so tennis clubs get tickets to ballot themselves. I usually get a ticket either through my tennis club or through the public ballot. And if worst comes to the worst and I don't get tickets, I have enough tennis friends to be able to go with someone else.