Caring for citrus trees involves planting in proper sunlight and soil, watering, fertiling, pruning, and managing pests.
Sunlight: Plant or place citrus trees in an area that receives 6 to 8 hours of direct sunlight daily.
Drainage: Ensure the soil drains well and the tree is slightly elevated or planted on a mound ("wet feet" or constantly saturated roots can damage the tree). Avoid burying the trunk below the graft union. 
Watering Guidelines
New Trees: Water young, newly planted citrus trees 2 to 3 times a week during the Spring and Summer seasons in warm climates to keep the root ball moist but not soggy.
Reduce the frequency in the Winter and as the tree grows and becomes established.
Hose - Use a hose to flood the watering well multiple times every time you water citrus trees
Fertilization
Timing: Feed trees regularly from early spring through late summer (such as monthly from February through September).
Nutrients: Use a balanced, citrus-specific fertilizer or an organic mix containing essential micronutrients like iron, zinc, and magnesium. Avoid fertilizing during extreme heatwaves.
Pruning & Maintenance
Sparing Pruning: Prune minimally—mostly to remove dead, damaged, diseased, or crossing branches. Heavy pruning can reduce fruit yields.
Suckers: Clip off any root suckers or water sprouts that emerge from below the graft union.
Mulch: Apply a 2- to 4-inch layer of organic mulch to retain moisture, keeping it 6 to 12 inches away from the trunk to prevent rot. 
Pests & Disease Control
Common Pests: Watch for aphids, scale, spider mites, and citrus leaf miners.
Treatments: Address mild infestations with insecticidal soap, horticultural oils, or neem oil applied in the evening.
Resources: For local guidance or specialized supplies, you can explore tips from Ashkan Jahanbin of Paradise Nursery directly at (818)406-8090 or our offices (818)701-5656
If you tell me whether your citrus tree is in a pot or planted in the ground and what specific type it is (like a lemon, orange, or lime), I can give you more tailored care steps.