Recommend tile adhesive & grout for small job

Some tiles on a boxed-in section in the kitchen recently became detached and I want to put them back on. In addition there are a few patches of grout elsewhere that I want to tidy up. I have managed to clean the old tiles without any problems.
I'm wondering what adhesive and grout to use. I've read that it is better to use a separate grout rather than a "tile and grout" all-in-1 kind of thing. However, it's only a small job, I'm not at all experienced in tiling and the kitchen is 14 years old so is not going to be immaculate whatever I do. I want something that is going to work and tidy it up a bit for another 3 or 4 years. The boxed in section that I need to reattach the tiles to is MDF by the way, in case that matters.
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