Also, built my first destroyer, need criticism.
Pikemen class Destroyer 28,650 tons 2812 Crew 5402.5 BP TCS 573 TH 1590 EM 600
5549 km/s Armour 5-83 Shields 20-300 Sensors 36/36/0/0 Damage Control Rating 21 PPV 86.58
Maint Life 7.14 Years MSP 4475 AFR 312% IFR 4.3% 1YR 154 5YR 2306 Max Repair 173 MSP
Ion Engine E7 (53) Power 60 Fuel Use 70% Signature 30 Armour 0 Exp 5%
Fuel Capacity 2,300,000 Litres Range 206.4 billion km (430 days at full power)
Gamma R300/16 Shields (10) Total Fuel Cost 160 Litres per day
Twin 12cm C4 Ultraviolet Laser Turret (6x2) Range 160,000km TS: 16000 km/s Power 8-8 RM 4 ROF 5 4 4 4 4 3 2 2 2 1 1
20cm C4 Ultraviolet Laser (4) Range 192,000km TS: 5549 km/s Power 10-4 RM 4 ROF 15 10 10 10 10 8 6 5 5 4 4
CIWS-160 (2x6) Range 1000 km TS: 16000 km/s ROF 5 Base 50% To Hit
Fire Control S12 72-16000 (2) Max Range: 144,000 km TS: 16000 km/s 93 86 79 72 65 58 51 44 37 31
Fire Control S06 96-6000 H70 (1) Max Range: 192,000 km TS: 6000 km/s 95 90 84 79 74 69 64 58 53 48
Gas-Cooled Fast Reactor Technology PB-1 PO-4.5 (15) Total Power Output 67.5 Armour 0 Exp 5%
Active Search Sensor MR21-R30 (70%) (1) GPS 1920 Range 21.0m km Resolution 30
Active Search Sensor MR3-R1 (70%) (1) GPS 64 Range 3.8m km Resolution 1
Thermal Sensor TH6-36 (70%) (1) Sensitivity 36 Detect Sig Strength 1000: 36m km
EM Detection Sensor EM6-36 (70%) (1) Sensitivity 36 Detect Sig Strength 1000: 36m km
This design is classed as a Military Vessel for maintenance purposes
Looks like a reasonable light frigate in size.
You look to be running an older version of Aurora, as you have a fire control larger than size 8 which is no longer possible(the size was halved in one of the last updates) and there is no intended deployment time listed. A lot of ship design advice has changed due to mechanics changes.
Some things that should still apply.
Maintenance life is excessive, unless this is intended to operate away from your territory for extended periods of time. Generally the only military vessels that need more than 1-2 years maintenance life are jump point defence bases and long range explorers. Also are you using maintenance storage bays? If so you would be better off replacing them with the same tonnage of engineering spaces, as those reduce the failure rate so you don't need as many maintenance supplies.
Fuel, again unless this is intended to operate far from resupply, has far too much. Aim for somewhere around 60-120 days fuel. This design isn't jump capable so you are going to need a jump ship along anyway, use it as a fuel tanker if you need to operate further out.
Weapons and fire controls look fine.
Sensors look fine if this is intended to operate on it's own. If it is intended to be part of a squadron, I'd strip off the res-30 active and the passives, place size 1 passives back on and move the larger sensors over to a dedicated sensor ship.
Armour is ok, although possibly a little thin for a beam combatant. Shields are ok for your tech level and in the current version of the game will help prevent shock damage from any missiles that leak through your PD.