Great advise musallio! Also, if you're having problems w/ timing, try playing w/ a metronome or a drum beat. A lot of newer keyboards have a metronome built into it (ie on my Casio, it's some of the last "rhythms").
Also, it's good to practice your scales and chords daily. When practicing your chords, practice playing chord progressions and the 7 basic triad chords in every key (ie I major, ii minor, iii minor, IV major, V major, vi minor, vii diminished). Learn to think of them in numbers as you practice. Also, learn new chords by numbers (ie instead of learning C major is C-E-G, learn that it's 1-3-5 of the C major scale). Also, when you learn new chords, learn their inversions too (ie Cmajor C-E-G, 1st inversion E-G-C, and G-C-E).
When practicing chord progressions, it's best to start practicing progressions using the primary chords, I-IV-V Chords, in every key. You'll play these chords probably 70-80 percent of the time in most songs (esp. basic praise/worship songs and hymns). With my experience playing on a worship team at church, I've noticed that we play these chords most of the time, and there's a lot of songs that will throw in one or two minor chords, most commonly the vii, and sometimes the iii, and sometimes the ii. The vii dim is rarely used in praise/worship (more likely to be used in gospel or preacher chords).