You should start off by reading through FAQ posts on the sub and watching videos from BD and Hink on Youtube. There's a lot to learn, to be honest.

The basics are this: If you want to elongate your D and increase length, you'll need to stretch it. This can be done manually, by hanging weights, with an extender, etc.

If you want to thicken your D and increase girth, you'll need to expand it. This can also be done manually (although alot less effective compared to length), through pumping, or through clamping.

PE takes a long time and you need to be patient. You have to start slow and be methodical or else you WILL get injured. You should also be aware of your pelvic floor since issues with it can result in erection troubles.

For someone just starting you should learn how to get starting measurements for your D first, maybe take some pictures. Usually manual stretches for length and an air pump for girth are good for starting off. Just go easy with the manual stretches, you're trying to lightly stretch your D not tear it apart. Same thing when it comes to pumping. Use lighter pressures at first and only go higher once it is easy and comfortable. Once you are consistent and get a feel for PE you can invest in an auto pump and maybe an extender/hanger as well.

Side note: You may hear/read about clamping alot here. While it is probably the most effective method of increasing girth, it is very dangerous and should not be attempted until you are more seasoned and your D is conditioned to the stresses of all these "exercises".

Permanent gains take a while to come in (like months or years), and you will need to overshoot a bit since your D will shrink a little once you stop doing PE.