Make a 4×4 grid

f	u	2	g
u	3	r	p
e	s	4	u
k	4	n	7

Nothing much to get a code. Looking at the letters you can see the keyword pursue. Reorder the columns like so: 2, 4, 1, 3

u	g	f	2
3	p	u	r
s	u	e	4
4	7	k	n

ugf23pursue447kn

Upper & lower case and numbers, rings a bell? Things are just not what they seem

With numbers, lower and upper case letters, Base64 has to be a good candidate.

Let’s split the string to make it more clear

rf 03 lod 03 dqvjstA 23 msv 06 25 n 10 07 g

Convert lower case to uppers case, numbers to letters (a=0) and uppercase to numbers (a=0)

RFdLODdDQVJST0xMSVgzNkhG

Convert Base64 to text

DWK87CARROLLIX36HF

Look at how the 0 are spread out. Notice anything ?

The o seem to be used has a delimiter. Split at all o and count the number of 1. If there are double zero, the count is zero

11111110	7
110	2
11111110	7
1111111110	9
11111110	7
110	2
111110	5
11110	4
111110	5
11111110	7
111111110	8
1110	3
111111110	8
11110	4
1111110	6
111110	5
1111110	6
1111110	6
11111110	7
1110	3
11111110	7
1111110	6
11111110	7
1110	3
111111110	8
11110	4
111111110	8
1111111110	9
111110	5
110	2
111110	5
1110	3
111110	5
0	0
1111111110	9
0	0
111111110	8
1111111110	9

72797254578384656673767384895253509089

Make pairs

72 79 72 54 57 83 84 65 66 73 76 73 84 89 52 53 50 90 89

Convert decimal to Ascii

HOH69STABILITY452ZY