Entirely up to you.
SD kits are pretty simplified. You can get by with just the stickers and they will look good enough. But if you want them to look better, some details and panel lines can be done to enhance the look. You can go as far as paint them if you wish. Depends on how detail oriented you want to be.
Kits before the original ZZ ones will look better painted, such as the “First Grade”, as some called, ones because they are like blank canvases even when assembled.
If you get into the HG, RG, MG, PG, and even newer SD kits, like ShadowsAndDust said, they are pretty much molded in different colors even on the same tree so you can get away with just stickers and decals, but panel lines are still recommended by most.
As with other model kits, you should probably pre assemble them before using glue. If you are confident enough to just use glue when assemble, that will be okay too, but just in case you change your mind about doing paint or not, modify it or not…
Anyway, you should definitely go with SD or HG for simplification, you can definitely go straight for RG, MG, and even PG if you wish, but those ones have more detail parts so you need to follow the instructions closely for those. SD and some HG are straightforward and lack of instruction probably will not result in disaster, just time to figure it out.