To me, praise is celebrating someone's gifts, like complimenting an artist or musician. Thanksgiving is gratitude for something, which maybe be someone's gift.
Wow! Your solo was terrific! (praise)
Thanks for blessing worship with your song! (thanksgiving)
The Book of Psalms is full of both. Let's look at some examples of praise:
The earth is the Lord’s and the fulness thereof,
the world and those who dwell therein;
for he has founded it upon the seas,
and established it upon the rivers.
Psalm 24: 1-2
Thy steadfast love, O Lord, extends to the heavens,
thy faithfulness to the clouds.
Thy righteousness is like the mountains of God,
thy judgments are like the great deep;
man and beast thou savest, O Lord.
Psalm 36: 5-6
Praise the Lord!
Praise God in his sanctuary;
praise him in his mighty firmament!
Praise him for his mighty deeds;
praise him according to his exceeding greatness!
Psalm 150: 1-2
Have you praised God lately, Dear Reader? I know sometimes it's hard. But what power can be found when we look beyond ourselves to celebrate our Creator and His creation!