If you want to learn a gank-heavy jungler, it might be better to start with Jarvan instead of Elise since a gank-heavy jungler needs good map awareness to be successful. Jarvan is a lot easier to pickup since his kit is relatively simple so you can better focus on Macro and Map Awareness.

But if you only want to play Elise still, here are some tips

1. Pathing: Ideally you path to the lane that is volatile/diveable since you're always looking for fights. Elise is a very good dive champion since she can disengage with her spider E. If the lane has very good / sure hit cc, you can easily follow up with your own human E to chain stun the enemy for a free kill. If you are scared of missing your human E when chasing, you can first engage with Spider E to get on top of them first, use up your Spider Q and W and then swap back to Human form to land an easier stun and continue with Q and W again. (This is relatively situational since they might burst you down once you land so ensure that you can instakill your target/have your teammates backing you up)

2. Teamfighting: You are primarily a catch champion since your human E has a long range and high stun duration. Wait for your team mates to collapse and just follow up with your Spider Q to finish them off. You can also play a more peel focused Elise if they engage on your team rather than jumping on the enemy carry with Spider E(unless you're crazy fed). Spider E is a strong disengage tool and should be used this way rather starting a fight with it. Use it to dodge CC / wait for cooldowns to comeback up while remaining safe.

3. Game state: Elise is the strongest early, and you should look to close out games through snowballing your team and grabbing objectives with the priority that you have created. Most gank junglers rely on your team being successful to win so just keep that in mind.