Any tips on Ike, I'm having trouble landing attacks and I played a Doctor Mario who destroyed be.
Forward tilt has decent range and is relatively quick to come out though you need to get a feel for the timing, also can KO at higher percentages.
You'll want to avoid using the ever tempting front smash unless you're sure you can catch someone out with it, Up smash however is very useful in some cases due to its sweeping arc that hits behind you as well, it tends to catch some people off guard at any rate. Ike's standard combo is one of his few other quick moves, does decent damage and the final sword strike will give you some space so don't be afraid to use it whenever the opportunity presents itself.
Quick draw can be more useful than it initially appears, it goes really far in this one compared to Brawl so the horizontal recovery is quite strong and you can aim to strike opponents guarding the edge as well as recover though this can be risky if they are prepared for it in which case try shooting over them with it instead if possible.
Aether is handy every now and then, it grants super armour and can trap the opponent within the move but can easily become predictable if used too often, it leaves you open afterwards so if you missed you'll likely get punished for it.
Eruption is not a move that's going to see much use in one on one, the blast area of the move does hit higher than it looks at least, may have some uses it hitting those returning to the stage at a specific angle of even as a surprise aerial entrance but for the most part I don't recommend this one.
Ike's aerials are really handy, the back air comes out deceptively quick and with good knock back, down air spikes if you get the opportunity to use it but keep in mind Ike's vertical recovery only goes so far which is to say it's risky to jump far out in an attempt to spike, forward air can be good at preventing other characters recoveries, return to the stage with a brief quick draw afterwards.
In some cases I found the down throw to be followed up well with Aether but I think this depends on the character you are against and at low percentages only, not a true combo but worth keeping in mind.
Really the best thing I can say about Ike is you play carefully, get used to the feel of his various sword swings, note which ones are relatively quick and which are slower. I find that playing it safe until the opportunity presents itself to land a good blow in (usually through aerials, jab combo or tilts) and then if possible rushing in to follow up can work pretty well. Ike hits hard so a few solid hits rack up damage quickly, just don't get too overzealous and know when to back off again. Keep in mind the reach of Ike's sword Ragnell is pretty decent and once again get a feel for the timing to hit opponents first with its range if they rush you.
Oh and there's a counter of course, unlike others it has a bit more startup lag (as they should!) so use it sparingly lest you become predictable.
I might not be the best for this sort of thing but hopefully some of this is useful.