Yes you can apply moisturizer and sunscreen at a time and LA SHEILD SPF 50 IS very good you can continue with this.
Serum you can use Salicylic serum from ordinary
Next Steps
For more best result you can share image of your face, so I can preview properly and advice more better skin care routine for oily and comedogenic skin. Book my consultation
Health Tips
do Hydrafacial on monthly basis it give you deep cleansing and reduce blackheads and whiteheads.