Ugh, I feel that! My first space marine looked like he fell face-first into the paint pot. A total thick, shiny blob where you couldn't see any details. Thinning your paints is legit the best first step, just like oliviak73 said. My second mini, after I tried that, was like night and day. Grab a cheap brush for dry brushing next, it makes armor look so good with zero effort.
Remember my first warhammer figure looked like it got dunked in a mud puddle. Thick globs of paint, a total mess. What helped was watching a few videos on thinning your paints with a little water, that was a game changer. Dry brushing is another good one to learn early for easy highlights. Honestly just stick with it, your next one will already look way better.