Peace be you.
=Understanding and having knowledge of Benevolence (His grants, helps) and Beauty (His Noble Attributes) of Allah,
=pay rights of His obedience through Holy Quran and Holy Prophet (peace and blessings of Allah) and obey what they have asked to obey,
=paying rights of Allah and Creature, being peaceful,
=pray,
=doing good, avoiding bad,
=conveying His Message,
=always remembering Him standing sitting reclining,
=trying to copy His noble attributes at humble human level,
=thanking Him, glorifying Him and praising Him,
=and more...
When one try to do these things, one is said to loving Allah.
[3:32]Say, ‘If you love Allah, follow me: then will Allah love you and forgive you your faults. And Allah is Most Forgiving, Merciful.’
[3:33]Say, ‘Obey Allah and the Messenger;’ but if they turn away, then remember that Allah loves not the disbelievers.
[3:58]‘And as for those who believe and do good works, He will pay them their full rewards. And Allah loves not the wrongdoers.’
[3:77]Nay, but whoso fulfils his pledge and fears God — verily, Allah loves the God-fearing.
[3;135]Those who spend in prosperity and adversity, and those who suppress anger and pardon men; and Allah loves those who do good;
[7:56]Call upon your Lord in humility and in secret. Surely, He does not love the transgressors.
and so many verses illuminate Whom Allah Loves.
When seeker continues to tread the path of righteousness, then Love Speaks in various ways, e.g:
[41:31]As for those who say, ‘Our Lord is Allah,’ and then remain steadfast, the angels descend on them, saying: ‘Fear ye not, nor grieve; and rejoice in the Garden that you were promised.
[46:14]Verily, those who say, ‘Our Lord is Allah,’ and then remain steadfast — no fear shall come upon them.
[19:97]Those who believe and do good deeds — the Gracious God will create love in their hearts. [Love from Allah to them, Allah for Allah in them, They love His creation, Creation love them.... recently Hazrat Ahmadiyya Khalifah explained this subject in a Friday sermon]
[2:187]And when My servants ask thee about Me, say: ‘I am near. I answer the prayer of the supplicant when he prays to Me. So they should hearken to Me and believe in Me, that they may follow the right way.’
and many other aspects which show love from both sides.
(Ref: translations from alislam.org)