what I would do is start working on barring chords. for example, instead of playing
-----
--1--
-----
--2--
--3--
-----
for C, try playing
e --3-- (optional)
B --5--
G --5--
D --5--
A --3--
E --x--
to play this you would use your index finger to play the notes on the 3rd fret and "bar" your pinky on the 5th fret. it'll be pretty uncomfortable at first and will take some time to build up strength in your pinky.
whatever note you play on the A string is the base of the chord. in this case, you're on the 3rd fret, so you're playing a C chord. in order to play a B chord, you would just move it back 1 fret. it should look like this:
--2-- (optional)
--4--
--4--
--4--
--2--
--x--
like I said, it'll take some time getting used to playing like this, but it's pretty essential when you get further down the line with playing