Yes, Oppo A5s does have a dedicated memory card slot. You can use up to 256GB MicroSD card in it. Besides, Oppo A5s also has OTG support.
No. Oppo A5s does not have the 5G network support.
Yes, Oppo A5s does have the fingerprint scanner. It also has the support for the face unlock.
No. Oppo A5s does not have the dual front camera but it has the dual rear camera set up.
Yes, Oppo A5s does have a 3.5mm headphone jack.