Hey! 
Good on you for reaching out for advice, and hopefully I can chime in with some non-leprotic content.
Apothecary + Willow seems like it should be able to get you through the quests fairly easily, although they’ll be a slog regardless. I guess I’m also not sure what Willow’s damage is without kingdom bonuses, etc., so maybe it’s not quite enough, although it does have an okay brown gem boost ratio.
Rock Spirit is another great suggestion, as per @Dust_Angel. Apothecary + Rock Spirit, and you’re good to go. You could even chuck Rock Spirit at the end after Willow to catch extra browns, and finish off anything that didn’t get killed by Willow.
Use the Merlantis/Trident banner (+2 
, +1 
, -1 
) to fill up Apothecary as quickly as possible - and if you don’t have it, unlocking Merlantis should be easy.
I’d also recommend using your Hero up the front with a non-mana blocking weapon (does this make sense to you?) to act as a tank and earn class exp. Upgrading one of the common/rare weapons will give you some bonus stats (e.g. Sword of Heroes +5).
And I think it probably is worth beelining the Forest of Thorns quest line to gain a copy of Rowanne, the troop several have mentioned - she can be a bit of a powerhouse in the right setup, early game.
You have a lot of good troops for your level! Which I guess comes from playing for a long time and just logging on daily for most of it 
.
@JLUONG’s suggested team was a good one, although perhaps better suited for stronger opponents, rather than pure speed. If you wanted to include the Hero, I’d probably substitute out Emperor Khorvash (with great sadness).
There are a couple of troop combinations that work as effective loopers (troops that can generate mana for each other without giving up the turn) for just about any situation, and you have most of them. Alchemist + Moneylender/Hellcat is one, and Green Seer + Diviner/Giant Spider is the other (Giant Spider being the only troop you don’t have, there). If you get stuck, see if you can make something around them.
There are also a few troops (from the ones you have) I’d recommend levelling up to level 5 so that you can sort by Level and keep an eye on them, as either useful mana generators for any team or just decently powerful troops early on. As follows:
Alchemist, Apothecary, Banshee, Clockwork Sphinx (
), Dark Maiden, Diviner, Forest Troll, Green Seer, Moneylender, Ranger, Rock Spirit, Templar, Valkyrie.
To a lesser extent:
Cockatrice, Deck Hand, Deep Borer, Dryad, Dwarven Gate, Dwarven Zombie, Fire Bomb, Fire Giant, Fire Lizard, Ice Worm, Midge Swarm, Paladin, Orc, Rock Worm, Snowy Owl, Wall of Bones.
I could do a third tier… Suffice to say, there will be other useful troops, depending on the situation. When making a team, I often find it useful to Filter by Spell Effect > Convert Gems, and/or then > Create/Destroy(/Remove) Gems.
I’d also recommend trying out the Warpriest class that you’ve unlocked - its level 10/third rank Talent, Brilliant Aura, can be very useful early on with looping-type teams (gives +2 to life on 4/5 matches), and it still has decent attack due to the War Talent Tree.
I’m going to just list a bunch of potential team combos to play around with or get ideas from, to finish off, as well as a link to this thread: What is the most OP Rowanne deck?. Hopefully you’ll find some of them useful.
- Crude Club, Apothecary, Willow, Rock Spirit (or Keeper of Souls)
- Crude Club, Apothecary, Green Seer, Willow
- Templar, Valkyrie, Rowanne, Prismatic Orb (weapon unlocked with mana masteries) (order can be switched to Purple Weapon, Valkyrie, Rowanne/Templar)
- Hero Weapon, Clockwork Sphinx, Dark Maiden, Rowanne (more fun than you might think) (Slayer Banner, from Dhrak-Zum, ideally)
- Sword of Heroes, Alchemist, Fire Lizard, Fire Giant (Bear or Lantern Banner) (super basic)
- Sword of Heroes, Alchemist, Moneylender/Hellcat, X (red or yellow damage dealer) (Bear or Lantern Banner).
- Crude Club, Green Seer, Diviner/Giant Spider, X (green or yellow/purple damage dealer) (Unicorn, Summer/Riven, Talon/Warren banner)