I'm not a master deckbuilder or anything myself, but I will lay out some tips for you as best I can. I'll be pretty honest and blunt, but only to help.
1) Cut all the green, it is creating confusion in the deck. You are building a boros deck (by the looks of it primarily red).
2) Mana base tips:
*You can't play that mana base and play
Goblin Chainwhirler. At most one land, maybe two, that cannot produce red.
*Your curve goes up to 5, so you start with 25 lands. That is the norm (without playing cards that
accelerate your mana).
*Here is a mana base better suited for your deck.
-Sacred Foundry x4,
Clifftop Retreat x4,
Boros Guildgate x4,
Evolving Wilds x2,
Plains x1, Mountains x10.
*Playing Guildgates is bad in standard, however if you want to play
Goblin Chainwhirler and
Lyra Dawnbringer in the same deck that requires at least 15 white sources of mana, and like i said to cast Chainwhirler turn three you want pretty much every land to provide red.
3) You are playing too many 3cmc creatures. Instead of playing the Skynight Legionnaire (it's not great) try playing x4 Chainwhirler, x4
Legion Warboss, and x2 Tajic (because it is legendary). That is still 10 3cmc creatures, but the are your best ones. ***If you find you are still drawing too many cut a Legion's Warboss.
4) One of your 1cmc creatures is very good and the other is pretty bad. Keep the
Goblin Banneret because the mentor and pump is really good in your deck. Drop the
Fire Shrine Keeper for something like
Fanatical Firebrand or
Ghitu Lavarunner (only Lavarunner if you play a lot of instants and sorceries, so Firebrand probably better here).
5) I was going to say cut the
Demotion, but it serves a purpose. I'd play straight removal myself, but to each their own.
6) You are playing 12 "support cards", cut it to 8. What I mean is that these are cards such as removal or card draw that cannot attack (which is your decks main objective). Maybe try x2
Risk Factor, x2
Lava Coil, x4
Lightning Strike. The ability to damage the opponent with
Lightning Strike is important for you as you are an aggressive deck and those 3 damage can finish a game.
*
Seal Away is not as good in your deck as in other decks since you are the aggressor and you want to remove blockers.
7) As far as a sideboard, you do have some decent pieces. Shalai and
Remorseful Cleric stay. Response is good, could be in the main deck instead. I'd play
Settle the Wreckage or Defeaning Clarion in the sideboard as a sweeper...Wreckage is one-sided so probably better for you if you play against other aggro decks.
banefire is great against control.
Experimental Frenzy is a whacky card that can go off pretty big against slower decks.
Conclave Tribunal is a nice
catch all in the sideboard, that you can convoke in this deck. Finally, play a couple
Shock to play against other aggro decks.
*The bones of the deck are really nice, it just needs some fine tuning. A good rule when building decks is to put together 28 cards first that fit the theme of your deck (creatures that pound face). These cards should be creatures or cards that help your creatures. Next add in 7/8 support cards (cards that give you card advantage-removal or card draw). Step 3 add your lands. Chainwhirler is a difficult one to do, but generally if you play a card that is 1RR then that requires 17 sources of red...it counts down by one source for each you go up the curve (2RR=16, 3RR=15,....)
*In the sideboard you want cards that answer particular threats or replace cards in your main deck that are weak aganst certain archetypes. What i mean by the second part is
Lava Coil does nothing against control, so you need a card to replace for that matchup.
Hope any of this was helpful. Good luck with your deck.