You are a medium range champion meaning that you can't poke but also don't have to go into melee range of other enemies. Lillia is truly an enigma to build because of the inconsistent items that she is given and how much stats she needs. She needs Mana, Ability Haste, Ability Power, Survivability, Movement Speed and Levels. The handicap of building Mana and Survivability at the same time is what causes her to be so bad with the Liandry build. She dies in one shot so she play so far back that she doesn't have true carry potential unless she is turbofed. She has insane over time damage meaning that her only counter is burst damage. Lillia is a squishy champion that given her team a consistent secondary source of damage but ends up not being able to influence teamfights as much as a primary damage source.

For me Lillia is a 1 v 5 machine that hard carries with CC, damage and frontlining but also dodging enough abilities that she doesnt have to go full tank. The game has too much CC for Lillia to build Liandry so I only go for Riftmaker which doesnt compromise too much damage (unlike crown).

The good thing with Lillia is that her stats aren't overbuffed like meta champions and doesnt impose an extremely unfair playstyle to get nerfed. She has enough counterplay for her to stay in a relatively good position for now.

The riftmaker build is only good when you are ahead of the enemy team, if you fall behind it is the definition of a death sentence. The beginner build is much more consistent but in my experience lacks the teamfight potential of a carry. You cannot play a champion that you have mastered and completely crush the enemy but instantly loose all carry potential the moment you played relatively aggressive. Lillia can't invade if she is building Liandry at any point of the game and she looses a lot of her strength to power farm better than any jungler in the game.

Although in the threats page of the guide there is only short range champions with busted base damage there are a few champion that you have to play around. Veigar, Gankplank and Khazix are the most notorius matchups for Lillia due to their crazy burst damage. They are some of the hardest champions to play around and can shut you down on their own.

Gankplank can one shot you after 3 items so camping him is mandatory

Veigar has unfair amounts of burst and is practically ungankable so camping the lanes with CC and tank is best.

Khazix can perma invade your jungle so getting vision on him and counterjungling him is mandatory to not fall behind.

She brings so much versatile and effective tools to the match and has significant carry potential. Team wide CC, AOE damage, Anti tank damage, Countering low mobility champions, Punishing solo carries is some of the tools she brings to the table. She has extremely high tempo meaning that a good Lillia and a Really good Lillia can differ by leaps and bounds. One of the problems with her is that she is has to be ahead of her enemy and at worst case has to be even. If you fall behind on Lillia due to spam ganking, having your jungle stolen, losing significant tempo due to dying on a gank can transform a match completely. Her knowledge ceilling is extremely high and is similar to Kindred's playstyle of outsmarting your opponents plus knowing matchups.

Lillia takes a lot of experience to break the "Akali ceiling". She can go 10+ kills but macro play is so much more important than kills that she will loose the matches where she goes 10 kills. Akali can win lane after level 6 against 80% of champions but transforming that lead to a game winning play takes a lot of practise. Influencing your lanes as Lillia is hard due to how squishy she is and how important your first item is as Lillia. Before first item, you dont have direct influence over the match and this is the part of Lillia that can take a really grim turn. An enemy assasin can get fed during the time when your influence is at its lowest so its your job to punish those plays. But this requires a great amount of knowledge meaning hat its going to take some time. Many people dont have the patience for this playstyle so they gravitate towards champions like Akshan, Akali, Rengar where you will see significant improvements within the first 20 matches. Lillia takes 100k Mastery before you even start to wake up as a jungler. I dont suggest it as your introduction to jungle due to its complexity and would suggest picks like diana and udyr instead before you venture out.