Bonding can take time. It is best if both rabbits are fixed (spayed or neutered) and given time to heal from that and have the hormones leave the body. This can be about 4-6 weeks after the surgery.
Choosing which rabbits does make a difference. Just like you will not get along with everyone, neither does every rabbit get along with all others. It is best to let your rabbit choose who they want to be with. If there is a rescue near you, they might allow you to bring your rabbit for bunny dates and let him pick out who he wants.
Generally, a male and female pair gets along best, then 2 females and finally 2 males. However, it depends a lot more on the personalities of the rabbits than the sex.
Once you get the rabbits and are ready to start bonding. It is best to start on neutral territory. This can be a bathroom or just an area that neither rabbit has claimed as theirs. A pen or way to limit the area is good especially if you have a lot of stuff in the area which could make it difficult to catch them if needed. Start with the rabbits on opposite sides of the pen so they can smell each other. If that goes well, you can put them in together, but you need to be in the pen too. If things go well, you can increase the amount of time they are together and can offer then food and such during this time.
Once they are getting along on neutral territory, you can move the bonding scession to the area you want them to be living. You may need to go back a few steps and work them back up as one may not be comfortable with the other in their area. I would keep the cages closed at first. Once they can be out for a few hours without issue, you can open the cages and let them in each others. Some people switch the rabbits in the cages every day so the rabbits get used to the others scent.
You can eventually get them in the same cage, but again do it gradually and make sure the cage is big enough for both.
Some rabbits can bond in a week or 2 and other can take months to fully bond and some just never bond.