First off you need to install forge 1.12.2 and the squake mod for 1.12.2 (both are under the resources tab). Once you have those installed just make a new flat world to practice in. The first step to bunny hopping is learning how to properly strafe. Quake style strafing is difficult for new players because it doesn't utilize the W key. To you first must walk forward then LET GO OF W and hold space bar. If you did this correctly you should just be jumping in a straight line next hold A and move your mouse to the left. Notice you might gain speed. Keep your strafing at sort of a medium pace but now do the same but for d and move your mouse to the right. If you chain those together you will gain speed and that's the sole purpose of bunny hopping. Now if you want to test your bhopping skills join our server and do the tutorial level minehop.tk:25764 .
If you need video help: https://www.youtube.com/watch?time_continue=73&v=fwt2j8toi4s&feature=emb_title